• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.93-93
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• 2009

실리콘 태양전지의 효율 향상을 위한 노력의 일환으로 결정질 실리콘 웨이퍼 표면passivation 물질 중 Atomic Layer Deposition (ALD)을 이용하여 증착한 $Al_2O_3$ 박막에 대한 관심이 증가하고 있다. 본 연구에서는 $Al_2O_3$ 박막의 증착 전 실리콘 웨이퍼의 산화막 두께에 따른 passivation 효과에 대해서 연구하였다. 실리콘 산화막은 $HNO_3$ 용액을 사용하여 화학적으로 생성시켰으며 $HNO_3$ 용액과의 반응 시간을 조절하여 실리콘 산화막의 두께를 조절하였다. 실리콘 산화막 생성 후 ALD로 $Al_2O_3$ 박막을 증착하였으며 증착 후 $N_2$ 분위기에서 annealing 하였다. Annealing 후 passivation 효과는 Quasi-Steady-State Photo Conductance를 사용하여 minority carrier의 lifetime을 측정하였다. Capacitance-Voltage measurement, Transmission Electron Microscopy, Ellipsometry를 사용하여 실리콘 산화막의 두께에 따른 $Al_2O_3$ 박막의 passivation 효과를 분석하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.406-406
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• 2011

최근 결정질 실리콘 태양전지 분야에서는 태양전지의 Voc와 Isc의 증가를 통한 효율 향상을 목적으로 후면 passivation 박막에 대한 연구가 활발하게 진행되고 있다. Local-Back Contact Cell은 최적화된 후면 passivation 박막을 이용한 태양전지 제조방법이다. 본 연구에서는 고효율의 LBC 태양전지 개발을 위해 Rapid Thermal Oxide(RTO)를 이용한 후면 passivation 박막에 screen printing을 이용한 point contact 구조의 LBC 태양전지를 제작하고 그 특성을 분석하였다. 본 연구에 사용된 RTO 박막은 O2와 N2, 2L/min의 조건에서 $850^{\circ}C$에서 3분 동안 열처리하여 성장시켰다. 이렇게 성장된 박막은 3nm의 두께로 형성되어 passivation 효과를 나타내었으며, carrier lifetime 측정 결과 37.8us의 값을 나타냈다. 전면 ARC형성을 위해 RTO 박막 위에 PECVD를 이용하여 SiNx passivation 처리를 하였고, 그 결과 carrier lifetime은 49.1us까지 향상하였다. 후면의 전극 형성을 위해 screen printing 방법으로 Al point contact을 형성하여 local 한 BSF를 형성 시켰으며, 이후 후면 전극 연결을 위한 방법으로 300nm의 두께로 full Al evaporation 공정을 진행 하였다. 결과적으로 RTO 후면 passivation 박막에 Al point contact 형성을 통해 제작된 태양전지는, Suns-Voc 579mV, FF 82.3%, 16.7%의 효율을 달성하였다.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.3
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• pp.51-57
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• 2019

To protect the Cu surface from oxidation in air, a two-step plasma process using Ar and $N_2$ gases was studied to form a copper nitride passivation as an anti-oxidant layer. The Ar plasma removes contaminants on the Cu surface and it activates the surface to facilitate the reaction of copper and nitrogen atoms in the next $N_2$ plasma process. This study investigated the effect of Ar plasma on the formation of copper nitride passivation on Cu surface during the two-step plasma process through the full factorial design of experiment (DOE) method. According to XPS analysis, when using low RF power and pressure in the Ar plasma process, the peak area of copper oxides decreased while the peak area of copper nitrides increased. The main effect of copper nitride formation in Ar plasma process was RF power, and there was little interaction between plasma process parameters.

• Electrical & Electronic Materials
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• v.10 no.6
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• pp.555-561
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• 1997

The passivation of n-GaAs(100) surface has investigated by photoreflectance(PR). The surface of the sample was treated with the 0.001 N solution Se/NH$_4$OH. After the surface treatment, the samples were annealed between 400 to $700^{\circ}C$ in a $N_2$atmosphere for 10 min. The intensity of PR signal and period of Franz-Deldysh oscillation(FKO) gradually decreased as the annealing temperature increased. The surface electric field(E$_{s}$) of the sample annealed at $600^{\circ}C$ is obtained 1.34$\times$10$^{5}$ V/cm. This value is 1.97 times less than that of unannealed sample. It has found that the passivation of surface occurred when the surface of the sample had been treated with Se/NH$_4$OH solution and annealed from 500 to $600^{\circ}C$. This result could be due to activation of elemental Se on the surface. It has also found that the elemental Se of the surface diffused about 100 $\AA$ into the bulk GaAs when Se-treated sample was annealed at $600^{\circ}C$.>.

• Current Photovoltaic Research
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• v.7 no.1
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• pp.15-20
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• 2019

Most high-efficiency n-type silicon solar cells are based on the high quality surface passivation and ohmic contact between the emitter and the metal. Currently, various metalization methods such as screen printing using metal paste and physical vapor deposition are being used in forming electrodes of n-type silicon solar cell. In this paper, we analyzed the degradation factors induced by the front electrode formation process using e-beam evaporation of double passivation structure of p-type emitter and $Al_2O_3/SiN_x$ for high efficiency solar cell using n-type bulk silicon. In order to confirm the cause of the degradation, the passivation characteristics of each electrode region were determined through a quasi-steady-state photo-conductance (QSSPC).

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.462-462
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• 2014

The effect of rear passivation for passivated emitter and rear cell (PERC) using ozone and H2O oxidant of atomic layer deposited (ALD) Al2O3 was studied by post-annealing in N2 and forming gas ambients. Rear surface of PERC solar cell was passivated by Al2O3 grown by ALD with ozone and H2O oxidant. Al2O3 grown by ALD with ozone oxidant has been known to have many advantages, such as lower interface defects, low leakage current density. Its passivation quality is better than Al2O3 with H2O. Al2O3 layer with 10 nm and 20 nm thickness was grown at $150^{\circ}C$ with ozone oxidant and at $250^{\circ}C$ with H2O oxidant. And then each samples were post-annealled at $450^{\circ}C$ in N2 ambients and at $850^{\circ}C$ in forming gas ambients. The passivation quality was investigated by measuring the minority carrier lifetime respectively. We examined atomic layer deposited Al2O3 such as growth rate, film density, thickness, negative fixed charge density at AlOx/Si interface, and reflectance. The influences of process temperature and heat treatment were investigated using Sinton (WCT-120) by Quasi-Steady State Photoconductance (QSSPC) mode. Ozone-based ALD Al2O3 film shows the best carrier lifetime at lower deposition temperature than H2O-based ALD.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.12
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• pp.1865-1869
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• 1990

N-Channel polysilicon MOSFETs (W/L=20/1.5, 3, 5.10\ulcorner) were fabricated using RTP (Rapid Thermal Processor) and hydrogen passivation. The N+ source, drain and gate were annealed and recrystallized using RTP at temperature of 1000\ulcorner-1100\ulcorner. But the active areas were not specially crystallized before growing the gate oxide. Without the hydrogen passivarion, excellent transistor characteristics (ON/OFF=5.10**6, S=85MV/DEC, IL=51pA/\ulcorner) were obtained for 1.5\ulcorner MOSFET. Also the transistor characteristics were improved by hydrogen passivation.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.335.2-335.2
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• 2016

The fixed negative charge of the Al2O3 passivation layer gives excellent passivation performance for both n-type and p-type silicon wafers. For the best passivation quality, annealing is known to be a prerequisite step and a lot of studies concerning annealing effect on the passivation characteristics have been performed. Meanwhile, for manufacturing a crystalline silicon solar cell, firing process is applied to the Al2O3 passivation layer. Therefore, study on not only annealing effect but also on firing effect is necessary. In this work, Al2O3 passivation performance (minority carrier lifetime) for p-type silicon wafer was evaluated with Quasi-Steady-State Photoconductance(QSSPC) measurement after annealing at different temperatures. For the samples which showed different aspects, C-V measurement was performed for the cause - whether it is due to the chemical effect or field-effect. The change in Al2O3 passivation property after firing processes was investigated and the mechanism for the change could be estimated.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.6
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• pp.53-57
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• 1985

Comparisons and analyses were made of the properties of double or triple passivation layer structures composed of APCVD SiOt or PSG and PECVD SiN films with various layer combinations and layer thicknesses. As a result of the analyses of the pro.peHics such as threshold-voltage shift, crack resistance, pinhole density, and moisture reslstancei a con-clusion was reached that the proper passivation layer structure is the double layer consisting of a 4,00$\AA$ or thicker PSG film and a 6,000$\AA$ SiN film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.332-333
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• 2009

In this paper, we have deposited silicon nitride films by plasma-enhanced chemical vapor deposition (PECVD). For films deposited under optimized conditions, the mechanism of plasma-enhanced vapor deposition of silicon nitride is studied by varying process parameters such as rf power, gas ratio, and chamber pressure. It was demonstrated that organic light-emitting diode(OLEDs) were fabricated with the inorganic passivation layer processing. We have been studied the inorganic film encapsulation effect for organic light-emitting diodes (OLED). To evaluate the passivation layer, we have carried out the fabrication of OLEDs and investigate with luminescence and MOCON.