• 한국결정성장학회지
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• 제9권5호
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• pp.486-492
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• 1999

본 실험에서는 D.C magnetron sputtering을 사용하여 Mn-Ir/Ni-Fe/buffer/Si 다층박막의 교환결합 자계와 보자력에 영향을 주는 인자를 미세구조의 관점에서 분석하였다. (111) 우선방위에 상관없이 모든 시편에서 155 Oe 이상의 교환결합 자계가 발생하였다. Mn-Ir/Ni-Fe 의 계면에서 Mn-Ir의 결정립 크기와 게면 거칠기가 Mn-Ir/Ni-Fe 다층박막의 교환결합 자계와 보자력에 가장 많은 영향을 주는 것을 알 수 있었다. Mn-Ir/Ni-Fe/Cu/Ni-Fe/buffer/Si spin-valve 다층박막에서 각 층의 두께와 하지층에 따른 자기저항비와 coulping field을 분석하였다. Mn-Ir(10 nm)/Ni-Fe(7.5 nm)/Cu(2 nm)Ni-Fe(6 nm)/Ta (5 nm)/Si에서 최대 자기저항비가 발생하였다. 강자성체의 결정립 크기가 거대자기저항비에 영향을 주는 것을 알 수 있었다. 그리고 계면 거칠기와 강자성체의 결정립 크기가 coulping field 에 많은 영향을 주는 것을 알 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.326-328
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• 1995

SiC buffer layers were grown on Si(100) substrates by ultra-high-vacuum electron cryclotron resonance plasma (UHV ECR plasma) from $CH_4/H_2$ mixture at 700$^{\circ}C$. The electron densities and temperature were measured by single probe. The axial plasma potentials measured by emissive probe had the double layer structure at positive substrate bias. Piranha cleaning was carried out as ex-situ wet cleaning. Clean and smooth silicon surface were prepared by in-situ hydrogen plasma cleaning at 540$^{\circ}C$. A short exposure to hydrogen plasma transforms the Si surface from 1$\times$1 to 2$\times$1 reconstruction. It was monitored by reflection high energy electron diffraction (RHEED). The defect densities were analysed by the dilute Schimmel etching. The results showed that the substrate bias is important factor in hydrogen plasma cleaning. The low base pressure ($5\times10^{-10}$ torr) restrains the $SiO_2$ growth on silicon surface. The grown layers showed different characteristics at various substrate bias. RHEED and K-ray Photoelectron spectroscopy study showed that grown layer was SiC.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.175-176
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• 2007

This paper describes on the characteristics of Pd thin films deposited on poly-crystalline 3C-SiC buffer layers for microsensors, in which the poly 3C-SiC was grown on Si, $SiO_2$, and AlN substrates, respectively, by APCVD using HMDS, $H_2$, and Ar gas at $1100^{\circ}C$ for 30 min. In this work, a Pd thin film was deposited on the poly 3C-SiC film by RF magnetron sputter. The thickness, uniformity, and quality of these samples were evaluated by SEM. Crystallinity and orientation of the Pd film were analyzed by XRD. Finally, Pd/poly 3C-SiC schottky diodes were fabricated and characterized by current-voltage measurements. From these results, Pd/poly 3C-SiC devices are promising for high temperature hydrogen sensors and other microsensors.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.122-122
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• 2000

Magnesium oxide is thermodynamically very stable, has a low dielectric constant and a low refractive index, and has been widely used as substrate for growing various thin film materials, particulary oxides of the perovskite structure. There has been a considerable interest in integrating the physical properties of these oxides with semiconductor materials such as GaAs and Si. In this regard, it is considered very important to be able to grow MgO buffer layers epitaxially on the semiconductors. Various oxide films can then be grown on such buffer layers eliminating the need for using MgO single crystal substrates. Vapor phase epitaxy of magnesium oxide has been accomplished on Si(001) substrates in a high vacuum chamber using the single precursor methylmagnesium tert-butoxide in the temperature range 750-80$0^{\circ}C$. For the epitaxy of the MgO films, SiC buffer layers had to be grown on Si(001). The films were characterized by reflection high energy electron diffraction (RHEED) in situ in the growth chamber, and x-ray diffraction (XRD), x-ray pole figure analysis, scanning electron microscopy (SEM), and x-ray photoelectron spectroscopy (XPS) after the growth.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.589-592
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• 1999

This paper describes direct $\mu$C-Si/CaF$_2$/glass thin film growth by RPCVD system in a low temperature for thin film transistor (TFT), photovoltaic devices. and sensor applications. Experimental factors in a low temperature direct $\mu$ c-Si film growth are presented in terms of deposition parameters: SiH$_4$/H$_2$ ratio, chamber total pressure, substrate temperature, rf power, and CaF$_2$ buffer layer. The structural and electrical properties of the deposited films were studied by means of Raman spectroscopy, I-V, L-I-V, X-ray diffraction analysis and SEM. we obtain a crystalline volume fraction of 61%, preferential growth of (111) and (220) direction, and photosensitivity of 124. We achieved the improvement of crystallinity and electrical property by using the buffer layers of CaF$_2$ film.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.108-109
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• 2006

ZnO semiconductor has a wide band gap of 3.37 eV and a large exciton binding energy of 60 meV, and displays excellent sensing and optical properties. In particular, ZnO based 1D nanowires and nanorods have received intensive attention because of their potential applications in various fields. We grew ZnO buffer layers prior to the growth of ZnO nanorods for the fabrication of the vertically well-aligned ZnO nanorods without any catalysts. The ZnO nanorods were grown on Si (111) substrates by vertical MOCVD. The ZnO buffer layers were grown with various thicknesses at $400^{\circ}C$ and their effect on the formation of ZnO nanorods at $300^{\circ}C$ was evaluated by FESEM, XRD, and PL. The synthesized ZnO nanorods on the ZnO film show a high quality, a large-scale uniformity, and a vertical alignment along the [0001]ZnO compared to those on the Si substrates showing the randomly inclined ZnO nanorods. For sample using ZnO buffer layer, 1D ZnO nanorods with diameters of 150-200 nm were successively fabricated at very low growth temperature, while for sample without ZnO buffer the ZnO films with rough surface were grown.

• 한국결정성장학회지
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• 제10권1호
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• pp.36-41
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• 2000

본 실험에서는 D.C magnetron sputtering을 사용하여 Ni-Fe/Co-Fe/Mn-Ir/Cu/buffer/Si 다층박막의 교환이방성에 관하여 연구하였다. 일반적인 Ni-Fe/Mn-Ir/buffer(Cu)/Si의 다층박막 구조는 낮은 교환결합 자계에 의하여 강자성체를 완전히 고착시키지 못한다. 따라서 Ni-Fe/Mn-Ir/buffer/Si 다층박막의 $H_{ex}$를 증가시키기 위해 하지층으로 Cu/Ta을 사용하여 Mn-Ir막의 결정립 부피를 증가시키고 Ni-Fe.Mn-Ir계면에 Co-Fe을 삽입하여 반강자성체/강자성체 계면에서의 epitaxy 경향을 향상시켜 2배 이상의 $H_{ex}$의 증가를 얻을 수 있었다. 또한 ferromagnete/Mn-Ir/buffer/Si의 다층박막 구조에서는 Mn-Ir거 두께에 따른 He일 변화 거동은 Mn-Ir/ferromagnete/buffer/Si다층박막구조와는 다른데 이와 같은 이유는 적층순서에 따라서 반강자성체 결정립의 부피분포와 계면에서의 교환결합 에너지가 차이가 나기 때문인 것으로 사료된다.

• 한국전기전자재료학회논문지
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• 제18권5호
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• pp.439-444
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• 2005

We investigated the structural and electrical properties of BLT films grown on Si covered with $ZrO_{2}$ buffer layer. The BLT thin film and $ZrO_{2}$ buffer layer were fabricated using a metalorganic decomposition method. The electrical properties of the MFIS structure were investigated by varying thickness of the $ZrO_{2}$ layer. AES and TEM show no interdiffusion and reaction that suppressed using the $ZrO_{2}$ film as a buffer layer The width of the memory window in the C-V curves for the MFIS structure decreased with increasing thickness of the $ZrO_{2}$ layer. It is considered that the memory window width of MFIS is not affected by remanent polarization. Leakage current density decreased by about four orders of magnitude after using $ZrO_{2}$ buffer layer. The results show that the $ZrO_{2}$ buffer layers are prospective candidates for applications in MFIS-FET memory devices.

• 한국세라믹학회지
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• 제34권4호
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• pp.373-379
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• 1997

A study on the deposition and characterization of BaTiO3 thin films on MgO-buffered Si(100) substrates by sputtering was conducted. The MgO buffer layers were investigated as a function of deposition temperature. At lower substrate temperature, the MgO layers were not fully crystalline, but a crystallized MgO layer with (001) preferred orientation was obtained at the substrate temperature of $700^{\circ}C$. Partially (00ι) or (h00) textured BaTiO3 films were obtained on Si(100) with the MgO buffer layer grown at 700ι. While, randomly oriented BaTiO3 films with large-scale cracks on the surface were made without the MgO layer. The crystallographic orientation, morphology and electrical properties between the BaTiO3 films on Si with and without the MgO layer were compared using the BaTiO3 film on MgO(100) single crystal substrate as a reference system. Also the favorable role of the MgO layer as a buffer for growing of oriented BaTiO3 films on Si substrates was confirmed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1277-1279
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• 1994

In the structure of ZnO/nip-SiC: H/metal substrate amorphous silicon (a-Si:H) solar cells, the effects of inserting a rear textured ZnO in the p-SiC:H/metal interface and a graded bandgap buffer layer in the i/p-SiC:H have been analysed by computer simulation. The incident light was taken to have an intensity of $100mW/cm^2$(AM-1). The thickness of the a-Si:H n, ${\delta}$-doped a-SiC:H p, and buffer layers was assumed to be $200{\AA},\;66{\AA}$, and $80{\AA}$, respectively. The scattering coefficients of the front and back ZnO were taken to be 0.2 and 0.7, respectively. Inserting the rear buffer layer significantly increases the open circuit voltage($V_{oc}$) due to reduction of the i/p interface recombination rate. The use of textured ZnO markedly improves collection efficiency in the long wavelengths( above ${\sim}550nm$ ) by back scattering and light confinement effects, resulting in dramatic enhancement of the short circuit current density($J_{sc}$). By using the rear buffer and textured ZnO, the i-layer thickness of the ceil for obtaining the maximum efficiency becomes thinner(${\sim}2500{\AA}$). From these results, it is concluded that the use of textured ZnO and buffer layer at the backside of the ceil is very effective for enhancing the conversion efficiency and reducing the degradation of a-Si:H pin-type solar cells.