• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.418.2-418.2
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• 2016

$Al_2O_3$ passivation layer has excellent passivation properties at p-type Si surface. This $Al_2O_3$ layer forms thin $SiO_2$ layer at the interface. There were some studies about inserting thermal oxidation process to replace naturally grown oxide during $Al_2O_3$ deposition. They showed improving passivation properties. However, thermal oxidation process has disadvantage of expensive equipment and difficult control of thin layer formation. Wet chemical oxidation has advantages of low cost and easy thin oxide formation. In this study, $Al_2O_3$/$SiO_2/Si(100)$ interface was formed by wet chemical oxidation and PA-ALD process. $SiO_2$ layer at Si wafer was formed by $HCl/H_2O_2$, $H_2SO_4/H_2O_2$ and $HNO_3$, respectively. 20nm $Al_2O_3$ layer on $SiO_2/Si$ was deposited by PA-ALD. This $Al_2O_3/SiO_2/Si(100)$ interface were characterized by capacitance-voltage characteristics and quasi-steady-state photoconductance decay method.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.64.1-64.1
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• 2011

다중접합 태양전지는 흡수대역이 다른 juntion으로 구성되어, 각각의 태양전지 간의 전류정합(current matching)이 효율 향상에 중요하다. 본 실험에서는 Top cell에 i-a-Si:H(Thinckness:100nm), Middle cell에는 i-a-SiGe:H(Thickness:800nm)을 적용하였고, bottom cell에는 i-${\mu}c$-Si:H(Thickness:1800nm), 수광부의 p-layer에 에 SiOx을 이용하여 triple juntion amorphous silicon solar cell(삼중접합태양전지)을 구현하였다. 이를 최적화 시키기 위해 ASA simulation을 이용하여 각 Cell의 intrinsic layer의 밴드갭을 가변하였다. 가변 결과 i-a-Si:H : 1.85 eV, i-a-SiGe:H: 1.6 eV, i-${\mu}c$-Si:H: 1.4 eV에서 태양전지 효율 14.5 %을 기록 하였다. 본 연구를 통해 Triple juntion cell에서의 intrinsic layer의 밴드갭 최적화를 구현해 볼 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.471-475
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• 2000

P-type (100) Si wafer patterned with 1000$\AA$ SiO$_2$island was used as substrate and the Si films were deposited under low pressure using Si$_2$H$_{6}$-H$_2$gas mixture where the total gas flow rate and deposition pressure were 16.6sccm and 3.5mtorr, respectively. In this condition, we selectively obtained high-quality epitaxial Si layer of the 350~1050$\AA$ thickness. In order to extend the incubation period, we kept high pressure H$_2$ environment without Si$_2$H$_{6}$ gas for few minutes after first incubation period and then we conformed the existence of second incubation period.iod.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.121-122
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• 2011

광도파로 기반 센서의 성능을 개선시키기 위해서는 코어와 클래딩 층의 굴절률 차를 크게 하여 표면감도를 향상시켜야 한다. 이를 위해 센서용 광도파로 코어 층을 위한 고굴절률 SiNx 박막을 플라즈마 화학기상증착(PECVD, plasma enhanced chemical vapor deposition)법을 이용하여 성장한 후 그 표면특성을 분석하였다. 이 때 플라즈마 화학기상증착 공정 조건 중 NH3 가스를 제외하여 Si 성분이 많은 고굴절률 SiNx 박막의 성장을 유도하고 He/SiH4 가스유량비를 0에서 100까지 변화시켜 SiNx 박막의 표면거칠기를 제어하였다. Si기판 위에 SiNx 박막을 10분 성장 후 BOE(buffered oxide etchant)로 선택식각하여 그 박막두께를 alpha step으로 측정하는 방법으로 He/SiH4 가스유량비 조건별 박막성장률을 계산하였다. 그 결과 He/SiH4 가스유량비 증가함에 따라 박막성장률이 33 nm/min에서 19 nm/min으로 선형적인 감소함을 알 수 있었다. 박막두께가 190 nm가 되도록 He/SiH4 가스유량비 조건별 SiNx 박막을 성장한 후 그 표면특성을 AFM (atomic force microscope)으로 관찰하였다. 이를 통해 He/SiH4 가스유량비가 50일 때 SiNx 박막의 표면거칠기가 최소가 됨을 알 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.747-750
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• 2000

In this work, we investigated the dependence of optical and electrical properties of amorphous hydrogenated SiC (a-SiC:H) films on annealing temperature(T$\sub$a/). The a-SiC:H films were deposited by PECVD(plasma enhanced vapor deposition) on coming glass, p-type Si(100) wafer using SiH$_4$+CH$_4$+N$_2$gas mixture. The experimental results have shown that the optical energy band gap(E$\sub$g/) of the a-SiC thin films unchanged in the range of T$\sub$a/ from 400$^{\circ}C$ to 600$^{\circ}C$. The Raman spectrum of the thin films, annealed at high temperatures, has shown that graphitization of carbon clusters and micro-crystalline silicon occurs. The current-voltage characteristics have shown good electrical properties at the annealed films.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05a
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• pp.173-176
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• 2005

Teijin사의 HT100-B60의 폴리카보네이트(polycarbonate) $100{\mu}m$, I-Component사의 PES(polyethersulfone) $200{\mu}m$, Ferrania사의 PAR(polyacrylate) $100{\mu}m$와 $200{\mu}m$를 사용하였다 열팽창계수의 차이로 인해 공정상 기판의 가열과 냉각시 열응력이 발생하여 기판의 크랙발생의 원인이 된다. 이를 최소화하기 위해 모든 공정이 시작하기 전에 pre-annealing을 통해 plastic 기판의 시간별 공정을 실시하였다. plastic film의 annealing time은 0h, 12h, 24, 40h, 50h, 60h, 70h, 80h으로 사간을 달리하여 오븐 안의 진공상태를 조성하여 실험하였다. Thermal evaporator로 Al을 약 170nm 증착하였으며 (주)동진 세미캠의 DTFR-1011s DR LCD용 감광액을 Spin Coating Spread(500rpm/6sec), Spin(3000rpm/20sec)으로 coating하였다.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.295-298
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• 1989

Using the anisotropic etching characteristics or $N_2H_4-H_2O$ solution, Si diaphragm was fabricated for the integrated sensor. The optimal composition and temperature of the solution in Si etching process was established to be 50mol% $N_2H_4$ in water at $105{\pm}2^{\circ}C$ for both higher etch rate(=$2.6{\mu}m/min$) and better surface quality of etched {100} planes. Under the optimal etching condition, the electrochemical etch stop technique was employed to form Si diaphragm for pressure sensor and diaphragm thickness was exactly controlled to $20{\pm}2{\mu}m$.

• Journal of the Korean Ceramic Society
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• v.41 no.3
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• pp.197-201
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• 2004

SiO$_2$ and SiON thick films were deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique on silicon wafer (100) using SiH$_4$ and $N_2$O as precursor gases. In this work, the influence of rf power, and rf bias power on the optical and physical properties of SiO$_2$ and SiON thick films is presented. The refractive index decreases with increasing rf power, and rf bias power. The refractive index of the films varied from 1.4493 to 1.4952 at wavelength at 1552 nm, with increasing rf power, the nitrogen content decreases while the oxygen content increases, in a manner that the O/N ratio increases approximately linearly.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.10
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• pp.817-821
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• 2000

In this work, we have investigated the dependence of annealing temperature(T$\_$a/) on optical and electrical properties of amorphous hydrogenated SiC(a-SiC:H) films. The a-SiC:H films were deposited on corning glass and p-type Si(100) wafer by PECVD (plasma enhanced vapor deposition) using SiH$_4$+CH$_4$+N$_2$ gas mixture. The experimental results have shown that the optical energy band gap(E$\_$opt/)of the thin films annealed at high temperatures have shown that the graphitization of carbon clusters and micro-crystalline silicon occurs. The current-voltage characteristics have shown good electrical properties at the annealed films.

• Journal of Surface Science and Engineering
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• v.29 no.6
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• pp.797-802
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• 1996

Hydrogenated amorphous silicon carbide (a-SiC:H) films have been deposited on unheated substrates by low frequency (50Hz) plasma using $SiH_4+CH_4+H_2$ gas mixtures. Deposition rate, refractive index, optical band gap, Vickers hardness and IR spectrum of the deposited a -SiC:H films have been measured for various rations of gas flow rates k(=$CH_4/SiH_4$, 0.5k4) with a constant $H_2$ flow rate (100sccm). As k increases, the deposition rate of the a-SiC:H films increases up to the maximum value of about 220nm/h at k=2.5, and then it decreases. The refractive index of the films was 2.6 for k=2.5, while the optical band gap of the films was 3.3eV for k=2.2. The maximum value of Vickers hardness of the films was 1500Hv at k=1. The infrared transmission measurement shows that the films contain both Si-C and Si-$CH_3$ bonds.