• Applied Science and Convergence Technology
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• 제23권5호
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• pp.284-288
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• 2014

We present tapered nanostructures fabricated on a selective area of gallium phosphide substrates for advanced optoelectronic device applications. A lithography-free fabrication process was accomplished by dry etching of metal nanoparticles. Thermal dewetting of micro-patterned metal thin films provides etch masks for tapered nanostructures. This simple process also allows the formation of plasmonic surfaces with corrugated shapes. Rigorous coupled-wave analysis calculations provide design guidelines for tapered nanostructures on gallium phosphide substrates.

• 대한전자공학회논문지
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• 제10권3호
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• pp.1-9
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• 1973

파일롯트 램프와 숫자표시를 목적으로 국내에서 처음으로 화합물반도체인 갈륨 인을 사용해서 발광다이오드를 만들었다. 이같이 만든 다이오드는 밝고 선명한 붉은 빛을 냈으며 발광하는데 필요한 순방향 바이아스 전류는 5mA 이하였다. 다이오드의 p-n 접합면은 n형 GaP 단결정 기판에 liquid phase epitaxy방법으로 성장시켰고 이때의 Ga 용액의 온도는 약 1300°K정도를 유지했다. 이렇게 하여 제조된 p-n 접합체에 wire bonding으로 ohmic contact시켜 다이오드를 제조했다. 칼륨인 발광다이오드는 매우 적은 전류로 발광되는 장점과 성장 반웅시 질소를 불순물로 doping시키면 녹색으로 발광되는 장점을 갖고 있으므로 앞으로 양산화의 전망이 매우 밝다.

• ETRI Journal
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• 제43권5호
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• pp.909-915
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• 2021

GaAs on Si grown via metalorganic chemical vapor deposition is demonstrated using various Si substrate thicknesses and three types of dislocation filter layers (DFLs). The bowing was used to measure wafer-scale characteristics. The surface morphology and electron channeling contrast imaging (ECCI) were used to analyze the material quality of GaAs films. Only 3-㎛ bowing was observed using the 725-㎛-thick Si substrate. The bowing shows similar levels among the samples with DFLs, indicating that the Si substrate thickness mostly determines the bowing. According to the surface morphology and ECCI results, the compressive strained indium gallium arsenide/GaAs DFLs show an atomically flat surface with a root mean square value of 1.288 nm and minimum threading dislocation density (TDD) value of 2.4×10⁷ cm^-2. For lattice-matched DFLs, the indium gallium phosphide/GaAs DFLs are more effective in reducing the TDD than aluminum gallium arsenide/GaAs DFLs. Finally, we found that the strained DFLs can block propagate TDD effectively. The strained DFLs on the 725-㎛-thick Si substrate can be used for the large-scale integration of GaAs on Si with less bowing and low TDD.

• 대한한방내과학회지
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• 제25권4호
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• pp.25-33
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• 2004

Objective : The effects of Indium-Gallium-Aluminium-Phosphide(InGaAlP) laser transcutaneous irradiation on heart rate variability(HRV) in healthy adults are investigated with power spectrum analysis(PSA) of HRV. Methods : The control group consisted of 20 healthy volunteers (10 men, 10 women). The experiment was divided into 5 different periods, the pre-1st laser period(10 minutes), the 1st laser period(30 minutes), the post-1st laser period(5 minutes), the 2nd laser period( 30 minutes) and the post-2nd laser period(30 minutes). HRV was measured for 5 minutes at the pre-1 st laser period, the post-l st laser period and the post-2nd laser period. The laser period is the period in which InGaAlP laser transcutaneous Irradiation treatment occurs. Results : 1. SDNN of volunteers at post-1st laser period and post-2nd laser period significantly increased compared with that of the pre- 1 st laser period. 2, Ln(VLF) at post-I st laser period significantly increased compared with that of pre-1st laser period, while Ln(HF) at post-2nd laser period significantly decreased compared with those of pre- I st laser period and post-1st laser period, 3. Ln(TP) at post-1st laser period and post-2nd laser period significantly increased compared with that of pre-1st laser period, 4, LF/HF Ratio at post-2nd laser period significantly increased compared with those of pre-1st laser period and post-1st laser period. But the other variables did not significantly change. Conclusions : The results suggest that InGaAlp laser transcutaneous Irradiation in healthy adults is associated with the autonomic nervous systems. Further study is needed for investigating the effects of laser irradiation on autonomic nervous systems.

• 한국전기전자재료학회논문지
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• 제11권1호
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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.

• Journal of Preventive Medicine and Public Health
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• 제32권4호
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• pp.467-472
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• 1999

본 연구는 반도체 산업에서 반도체소자로서 주목받고 있는 GaAs, InP및 InAs의 세포독성을 평가하기 위해 햄스터의 폐포 대식세포를 사용하여 in vitro 자계 측정, LDH 활성치측정 및 세포의 형태학적 관찰 등을 검토하였다. 세포자계측정 결과 GaAs, InP 및 InAs첨가군 모두 대조군(PBS첨가군)에 비해 완화곡선이 유의하게 지연되었으며, 특히 GaAs 첨가군은 농도증가에 따라 용량의존적으로 완화곡선이 지연되는 경향이었다. 자화 후 2분간의 완화계수는 대조군에 비해 GaAs 첨가군은 농도증가에 따라 유의하게 낮아지는 용량의존성이 높은 경향이었으나, InP 및 InAs 첨가군에서는 모두 유의성이 인정되지 않았다. LDH활성치는 GaAs, InP 및 InAs첨가군 모두 용량 의존적으로 점차 높아지는 경향이었다. 세포의 형태학적 관찰소견은 GaAs첨가군에서는 용량의존적으로 세포막의 현저한 파괴, 핵의 형태적 변화 등 심한 세포장해가 유발된 반면, InP첨가군과 InAs첨가군에서는 세포내의 구조는 유지되었으나 세포질의 변성이 관찰되었다. 결과적으로 GaAs는 InP나 InAs보다 폐포 대식세포의 세포독성이 강한 것으로 보인다.