• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.54 no.11
• /
• pp.490-492
• /
• 2005

A study on radiation hardening of infrared(IR) detector, the chief component of IR camera was performed. The radiation test on IR sensor passivated with the ZnS by Co$^{60}$ gamma-ray over 1 Mrads showed the reduction in Ro by 1/100 which was related to the noise level. This effect that was caused by carrier trapping in the ZnS passivation layer increased the leakage current and resulted in degradation in the device performance. For the radiation hardening of IR devices we suggested the ones with CdTe passivation layer which had a tendency to reluctant to carrier trapping in its layer and developed test patterns. Radiation test to the patterns showed that the our CdTe passivated device could survived over 1 Mrad gamma-ray dose.

• Proceedings of the KIEE Conference
• /
• 2001.11a
• /
• pp.20-21
• /
• 2001

실리콘 나노결정 박막은 Nd:YAG 레이저를 사용한 펄스레이저 증착법으로 p형 (100) 실리콘 기판위에 형성되였다. 증착 후, 다양한 분위기 가스와 $400^{\circ}C$에서 $800^{\circ}C$까지 범위의 여러 온도에서 후열 처리가 수행되었다. 후열 처리가 끝난 시료 중 일부는 혼합가스(95 % $N_2$ + 5 % $H_2$)에서 한시간 동안 수소 passivation을 수행하였다. 실온에서 강한 청자색 photoluminescence (PL)을 관찰할 수 있었다. 이 논문에서 우리는 다양한 후열처리 조건과 수소 passivation 효과에 따른 PL 특성 변화를 제시하고, 이 결과를 통해 실리콘 나노결정 박막의 발광 메카니즘을 간접적으로 유추하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.11 no.7
• /
• pp.517-521
• /
• 1998

After etching Al-Cu alloy films using $SiCl_4/Cl_2/He/CHF_3$ plasma, a corrosion phenomenon on the metal surface has been studied with XPS(X-ray pheotoelectron spectroscopy) and SEM (Scanning electron microscopy). In Al-Cu alloy system, the corrosion occurs rapidly on the etched surface by residual chlorine atoms. To prevent the corrosion, $CHF_3$ plasma treatment subsequent to the etch has been carried put. A passivation layer is formed by fluorine-related compounds on the etched Al-Cu surface after $CHF_3$ treatment, and the layer suppresses effectively the corrosion on the surface as the $CHF_3$treatment in the pressure of 300m Torr.

• Ceramist
• /
• v.21 no.1
• /
• pp.24-43
• /
• 2018

Organic-inorganic halide perovskite materials have attracted significant attention during the last few years because of their superior properties for electronic and optoelectronic devices, such as their long charge carrier diffusion lengths and high photoluminescence quantum yields of up to 100% with tunable bandgaps over the entire visible spectral range. In addition to solar cells, light emitting diodes (LEDs) represent a fascinating application for halide perovskite materials. In this study, we review the recent progress in halide perovskite LEDs. The current strategies for improving the performance of halide LEDs, focusing on morphological engineering, dimensional engineering, compositional engineering, surface passivation, interfacial engineering, and the plasmonic effect are discussed. The challenges and perspectives for the future development of halide perovskite LEDs are also considered.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.05a
• /
• pp.58-61
• /
• 2005

In an effort to improve the electrical properties of ZnO:Al transparent electrode films, post-annealing treatment in hydrogen atmosphere was attempted with varying annealing time at 573 K for compatibility with typical display device fabrication processes. It was observed that carrier concentrations and mobilities increased with longer annealing time with small changes in crystallinity. This resulted in substantial decrease in resistivity from $4.80{\times}10^{-3}$ to $8.30{\times}10^{-4}{\Omega}cm$ due to increased carrier concentration. Such improvements in electrical properties are attributed to the passivation of the grain boundary surfaces. The optical properties of the films, which changed in accordance with the Burstein-Moss effect, were consistent with the observed changes in electrical properties.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2007.05a
• /
• pp.24.1-24.1
• /
• 2007

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.84-84
• /
• 2010

In this study, we report on the novel lithographic patterning method to fabricate organic-semiconductor devices based on photo and e-beam lithography with well-known silicon technology. The method is applied to fabricate pentacene-based organic field effect transistors. Owing to their solubility, sub-micron sized patterning of P3HT and PEDOT has been well established via micromolding in capillaries (MIMIC) and inkjet printing techniques. Since the thermally deposited pentacene cannot be dissolved in solvents, other approach was done to fabricate pentacene FETs with a very short channel length (~30nm), or in-plane orientation of pentacene molecules by using nanometer-scale periodic groove patterns as an alignment layer for high-performance pentacene devices. Here, we introduce the atomic layer deposition of $Al_2O_3$ film on pentacene as a passivation layer. $Al_2O_3$ passivation layer on OTFTs has some advantages in preventing the penetration of water and oxygen and obtaining the long-term stability of electrical properties. AZ5214 and ma N-2402 were used as a photo and e-beam resist, respectively. A few micrometer sized lithography patterns were transferred by wet and dry etching processes. Finally, we fabricated sub-micron sized pentacene FETs and measured their electrical characteristics.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.299.2-299.2
• /
• 2013

We investigated the potassium remaining on a crystalline silicon solar cell after potassium hydroxide (KOH) etching and its effect on the lifetime of the solar cell. KOH etching is generally used to remove the saw damage caused by cutting a Si ingot; it can also be used to etch the rear side of a textured crystalline silicon solar cell before atomic layer-deposited Al2O3 growth. However, the potassium remaining after KOH etching is known to be detrimental to the efficiency of Si solar cells. In this study, we etched a crystalline silicon solar cell in three ways in order to determine the effect of the potassium remnant on the efficiency of Si solar cells. After KOH etching, KOH and tetramethylammonium hydroxide (TMAH) were used to etch the rear side of a crystalline silicon solar cell. To passivate the rear side, an Al2O3 layer was deposited by atomic layer deposition (ALD). After ALD Al2O3 growth on the KOH-etched Si surface, we measured the lifetime of the solar cell by quasi steady-state photoconductance (QSSPC, Sinton WCT-120) to analyze how effectively the Al2O3 layer passivated the interface of the Al2O3 layer and the Si surface. Secondary ion mass spectroscopy (SIMS) was also used to measure how much potassium remained on the surface of the Si wafer and at the interface of the Al2O3 layer and the Si surface after KOH etching and wet cleaning.

• Journal of the Microelectronics and Packaging Society
• /
• v.25 no.4
• /
• pp.75-81
• /
• 2018

The effect of $Ar-N_2$ plasma treatment on Cu surface as one of solutions to realize reliable Cu-Cu wafer bonding was investigated. Structural characteristic of $Ar-N_2$ plasma treated Cu surface were analyzed using X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscope. Ar gas was used for a plasma ignition and to activate Cu surface by ion bombardment, and $N_2$ gas was used to protect the Cu surface from contamination such as -O or -OH by forming a passivation layer. The Cu specimen under high Ar partial pressure plasma treatment showed more copper oxide due to the activation on Cu surface, while Cu surface after high $N_2$ gas partial pressure plasma treatment showed less copper oxide due to the formation of Cu-N or Cu-O-N passivation layer. It was confirmed that nitrogen plasma can prohibit Cu-O formation on Cu surface, but nitrogen partial pressure in the $Ar-N_2$ plasma should be optimized for the formation of nitrogen passivation layer on the entire surface of Cu wafer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.05c
• /
• pp.45-48
• /
• 2003

The polishing mechanism of W-CMP process has been reported as the repeated process of passive layer formation by oxidizer and abrasion action by slurry abrasives. Thus, it is important to understand the effect of oxidizer on tungsten passivation layer in order to obtain higher removal rate (RR) and very low non-uniformity (NU%) during W-CMP process. In this paper, we investigated the effects of oxidizer on W-CMP process with three different kinds of oxidizers, such as $H_2O_2$, $Fe(NO_3)_3$, and $KIO_3$. In order to compare the removal rate and non-uniformity of three oxidizers, we used alumina-based slurry of pH 4. According to the CMP tests, three oxidizers showed different removal mechanism on tungsten surface. Also, the microstructures of surface layer by AFM image were greatly influenced by the slurry chemical, composition of oxidizers. The difference in removal rate and roughness of tungsten surface are believed to caused by modification in the mechanical behavior of $Al_2O_3$ abrasive particles in CMP slurry. Our stabilized slurries can be used a guideline and promising method for improved W-CMP process.