• 한국전기전자재료학회논문지
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• 제11권3호
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• pp.214-220
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• 1998

ZnO varistors are characterized by the features of excellent nonlinearity and surge withstand capability. In this paper, in order to investigate the use of ZnO varistor as surge absorption device in low voltage, metal oxide material($TiO_2$) was selected as control material of grain growth. Samples of ZnO varistors were fabricated with varying the contents, and then the microstructures and V-I characteristics were measured. It was observed by SEM that the mean grain size increased with the increase of the additive. From the measurement of V-I characteristics, it was observed that according to the increase of the quantity of $TiO_2$ as additive, the operating voltage was lowered.

• 한국전기전자재료학회논문지
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• 제33권1호
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• pp.25-30
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• 2020

Oxide (SiO₂)/Metal(Ag)/Oxide(SiO₂, ITO, ZnO) multilayer films were fabricated using a magnetron sputtering technique at room temperature on Si (p-type, 100) and a glass substrate. The electrical and optical properties of the asymmetric multilayer films depended on the thickness of the mid-layer film and the type of oxide in the bottom layer. As the metal layer becomes thicker, the sheet resistance decreases. However, the transmittance decreases when the metal layer exceeds a threshold thickness of approximately 10~12 nm. In addition, the sheet resistance and transmittance change according to the type of oxide in the bottom layer. If the oxide has a large resistivity, the overall sheet resistance increases. In addition, the anti-reflection effect changes according to the refractive index of the oxide material. The optical and electrical properties of multilayer films were investigated using an ultraviolet visible (UV-Vis) spectrophotometer and a 4-point probe, respectively. The optimum structure is SiO₂ (30 nm)/Ag (10 nm)/ZnO (30 nm) multilayer, with the highest FOM value of 7.7×10^-3 Ω^-1.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.269-269
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• 2007

최근 평판디스플레이 산업이 성장함에 따라 품질향상을 위한 연구가 활발히 진행중이며 또한, 부품 소재 개발에 박차를 가하고 있다. 대형 평판디스플레이 중 낮은 전력소모와 광시야각이 우수한 TFT-LCD가 각광받고 있다. TFT-LCD 소자의 투명전극으로 사용되기 위해서는 면저항 10~1k Ohm/sq., 광투과율 85% 이상의 특성이 요구되며 ITO(Indium Tin Oxide의 약자) 타겟을 스퍼터링한 박막이 일반적으로 사용되고 있다. 본 연구에서는 $In_2O_3$ 나노 분말 제조 공법으로 제작된 ITO 타겟을 사용하여 양산성 및 대형화에 적합한 DC 마그네트론 스퍼터 방식으로 투명전극을 제조하였다. 일반적으로 사용되는 고정식 DC 마그네트론 스퍼터 방식은 타겟표면에 재증착(back deposition)되는 저급산화물로 인해 이물 또는 노즐(Nodule) 이 형성되고 이로 인해 비이상적이고 불안정한 방전 플라즈마가 박막의 특성을 저하시킨다. 이러한 문제점을 해결하기 위해 이동식 DC 마그네트론 스퍼터 방식을 채택하였으며 대형 타겟을 이용한 대형화 기판 제작과 안정적인 sputter yield로 인해 uniformity가 우수한 ITO 박막을 제조하였다. ITO 박막의 저면저항 고투과율 특성을 구현하기 위해 공정변수인 산소분압, 전류밀도(DC power) 그리고 증착온도에 따른 ITO 박막의 미세조직과 결정성을 관찰하였으며 전기적 특성을 분석하였다.

• Journal of Welding and Joining
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• 제9권4호
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• pp.17-27
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• 1991

The direct brazing technology which could be used for the simplification of brazing process and the improvement of brazed joint quality was studied with $Al_2O_3$ and stainless steels. The brazing of $Al_2O_3$ to STS304 or STS430 was performed under different brazing conditions such as brazing filler metal, temperature, heating rate and brazing time. Microstructural observation and chemical analysis be SEM/EPAM were carried out to verify the quality of brazed joints. 4-point bending strength of brazed joints was also measured to find the optimal brazing conditions. The results showed that, in brazing of $Al_2O_3$, the mixed oxide layer resulted from the reaction between Ti in filler metal and oxide layer on the material surface to be brazed was found to be bery important for the joint quality. The width of oxide layer varied with the brazing conditions such as brazing time, heating rate and chemical composition of filler metals. The strength of brazed joints was more affected by the type of materials and their thermal properties than by brazing heat cycle.

• 한국결정성장학회지
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• 제10권6호
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• pp.412-417
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• 2000

High electric field stressed trap distributions were investigated in the thin silicon oxide of polycrystalline silicon gate metal oxide semiconductor capacitors. The transient currents associated with the off time of stressed voltage were used to measure the density and distribution of high voltage stress induced traps. The transient currents were due to the discharging of traps generated by high stress voltage in the silicon oxides. The trap distributions were relatively uniform near both cathode and anode interface in polycrystalline silicon gate metal oxide semiconductor devices. The stress generated trap distributions were relatively uniform the order of $10^{11}$~$10^{12}$ [states/eV/$\textrm{cm}^2$] after a stress. The trap densities at the oxide silicon interface after high stress voltages were in the $10^{10}$~$10^{13}$ [states/eV/$\textrm{cm}^2$]. It was appeared that the transient current that flowed when the stress voltages were applied to the oxide was caused by carriers tunneling through the silicon oxide by the high voltage stress generated traps.

• 한국전기전자재료학회논문지
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• 제13권9호
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• pp.729-734
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• 2000

Recently, Very Large Scale Integrated (VLSI) circuit & deep-submicron bulk Complementary Metal Oxide Semiconductor(CMOS) devices require gate electrode materials such as metal-silicide, Titanium-silicide for gate oxides. Many previous authors have researched the improvement sub-micron gate oxide quality. However, few have reported on the electrical quality and reliability on the ultra thin gate oxide. In this paper, at first, I recommand a novel shallow trench isolation structure to suppress the corner metal-oxide semiconductor field-effect transistor(MOSFET) inherent to shallow trench isolation for sub 0.1${\mu}{\textrm}{m}$ gate oxide. Different from using normal LOCOS technology deep-submicron CMOS devices using novel Shallow Trench Isolation(STI) technology have a unique"inverse narrow-channel effects"-when the channel width of the devices is scaled down, their threshold voltage is shrunk instead of increased as for the contribution of the channel edge current to the total channel current as the channel width is reduced. Secondly, Titanium silicide process clarified that fluorine contamination caused by the gate sidewall etching inhibits the silicidation reaction and accelerates agglomeration. To overcome these problems, a novel Two-step Deposited silicide(TDS) process has been developed. The key point of this process is the deposition and subsequent removal of titanium before silicidation. Based on the research, It is found that novel STI structure by the SEM, in addition to thermally stable silicide process was achieved. We also obtained the decrease threshold voltage value of the channel edge. resulting in the better improvement of the narrow channel effect. low sheet resistance and stress, and high threshold voltage. Besides, sheet resistance and stress value, rms(root mean square) by AFM were observed. On the electrical characteristics, low leakage current and trap density at the Si/SiO$_2$were confirmed by the high threshold voltage sub 0.1${\mu}{\textrm}{m}$ gate oxide.

• E2M - 전기 전자와 첨단 소재
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• 제16권9호
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• pp.61.2-61
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• 2003

• 한국전기전자재료학회논문지
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• 제11권10호
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• pp.778-783
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• 1998

Film characteristics of thin ONO dielectric layers for MONOS(metal-oxide-nitride-oxide-semiconductor) EEPROM was investigated by TEM, AES and AFM. Seocnd derivative spectra of Auger Si LVV overlapping peak provide useful information fot chemical state analysis of superthin film. The ONO film with dimension of tunnel oxide 23$\AA$, nitride 33$\AA$, and blocking oxide 40$\AA$ was fabricated. During deposition of the LPCVD nitride film on tunnel oxide, this thin oxide was nitrized. When the blocking oxide was deposited on the nitride film, the oxygen not only oxidized the nitride surface, but diffused through the nitride. The results of ONO film analysis exhibits that it is made up of $SiO_2$ (blocking oxide)/O-rich SiON(interface)/N-rich SiON(nitride)/ O-rich SiON(tunnel oxide)

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.119-119
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• 2008

The electrical characteristics of Metal-Ferroelectric-Nitride-Oxide-Silicon (MFNOS) structure is studied and compared to the conventional Silicon-Oixde-Nitride-Oxide-Silicon (SONOS) capacitor. The ferroelectric blocking layer is SrBiNbO (SBN with Sr/Bi ratio 1-x/2+x) with the thickness of 200 nm and is fabricated by the RF sputter. The memory windows of MFNOS and SONOS capacitors with sweep voltage from +10 V to -10 V are 6.9 V and 5.9 V, respectively. The effect of ferroelectric blocking layer and charge trapping on the memory window was discussed. The retention of MFNOS capacitor also shows the 10-years and longer retention time than that of the SONOS capacitor. The better retention properties of the MFNOS capacitor may be attributed to the charge holding effect by the polarization of ferroelectric layer.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.331-332
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• 2005

Ozone is ambient gas which is useful for the fabrication of metal oxide thin films under conditions of molecular beam epitaxy. Ozone is condensed by the adsorption method and its concentration is analyzed using the thermal decomposition method. The concentration of ozone exceeds 90 mol% and ozone is supplied for a sufficiently long time to grow oxide thin films. The ozone concentration is also evaluated using a quadrupole mass analyzer and the accuracy of this method is compared with the results of the thermal decomposition method.