• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.173.2-173.2
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• 2014

Thin nitride thin films were synthesized by reactive radio-frequency magnetron sputtering in the ultra high vacuum (UHV) chamber. To control the characteristics of thin films, tin nitride thin films were obtained various argon and nitrogen gas mixtures, especially low nitrogen gas ratios. Tin nitride thin films were analyzed with alpha step, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and 4 point probe measurement. The result of alpha step and SEM showed that the thickness of thin nitride thin films were decreased with increasing nitrogen gas ratios. The metallic tin structure was decreased and the amorphous tin nitride structure were observed by XRD with higher nitrogen gas ratios. The oxidation state of tin and nitride were studied with high resolution Sn 3d and N 1s XP spectra.

• 한국세라믹학회지
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• 제35권2호
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• pp.115-122
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• 1998

The effect of sintering conditions on the sinterability for silicon nitride has been studied by many in-vestigators. However the effect of sintering conditions on the machinability which is the major barrier to the field applications of the ceramic components has not been fully studied. In this study the sintering con-ditions such as temperature gas pressure and time in silicon nitride were varied. The physical and mechan-ical properties of the gas pressure sintered (GPS) silicon nitride were measured. The optimum mi-crostructure of silicon nitride with the excellent machinability was investigated by MFG(magnetic-fluid grinding) technique. An attempt was made to figure out how the mechanical properties influence upon the machinability of silicon nitride ball.

• 한국표면공학회지
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• 제44권3호
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• pp.75-81
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• 2011

Growth behaviors of iron-nitride on S45C steels at low pressure gas nitriding were examined. Surfaces of the steels covered with fine and porous oxide during the pre-oxidation using $N_2O$ gas. Well faceted particles connected with them were observed after 1 min nitriding. They grew steadily and filled inter-pores during additional nitriding process. From the X-ray diffraction analysis, ${\gamma}'$-iron nitride was dominantly formed at the initial stage but the amount of ${\varepsilon}$-iron nitride was rapidly increased as nitriding treatment time. The porous layer was formed on the particles and thickened up to half of nitride layer after 60 min nitriding. The observed growth behaviors were discussed in internal stress related with volume expansion involved in transforming from iron to iron-nitrides.

• The Korean Journal of Ceramics
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• 제6권4호
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• pp.364-369
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• 2000

Silicon nitride with adding La$_2$O$_3$ was sintered by gas pressure sintering (GPS) technique at $1950^{\circ}C$, in $N_2$ gas at 3 MPa, for 2h. Mechanical properties such as hardness, flexural strength, and fracture toughness were determined as a function of the GPS holding time and the contents of La$_2$O$_3$ in silicon nitride. Also machinability of silicon nitride ball with various GPS holding time and amount of La$_2$O$_3$ was evaluated by magnetic fluid grinding (MFG) method. In this study it was found that machinability was influenced significantly with La$_2$O$_3$ contents. However, the different GPS holding time did not affect the machinability very much.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.94-97
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• 1997

We investigated the sheet resistance properties of tungsten nitride thin films deposited by RF and DC sputtering system. It deposited at various conditions that determine the sheet resistance. The properties of the sheet resistance of these films were measured under various conditions. Sheet resistance analysed under the flow rate of the argon gas and contents of nitrogen from nitrogen-argon gas mixtures. We found that these sheet resistance were largely depend on the temperature of substrate, gas flow rate and RF power. Very high and low sheet resistance of tungsten films obtained by DC sputtering. As the increase of contents of nitrogen gas obtained from nitrogen-argon gas mixture, tungsten nitride thin films deposited by the reactive DC sputtering and the sheet resistance of these films were increased.

• 한국세라믹학회지
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• 제34권3호
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• pp.249-256
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• 1997

100-500KHz범위의 주파수전원을 인가하여 발생한 플라즈마를 이용하여 질화붕소(boron nitride)막의 합성시 육방정상(hexagonal phase)과 입방정상(cubic phase)의 생성거동을 관찰하였다. BCl3와 NH3를 붕소와 질소의 공급기체로 선택하였고 Ar과 수소를 carrier기체로 사용하였다. 합성변수로는 플라즈마전원의 전압, 기판의 bias, 합성압력, 기체의 조성, 기판의 온도이었는데, 합성된 박막은 FT-IR결과로부터 육방정과 입방정의 혼합상으로 나타났고, 각 상의 분률은 변수의 크기에 의존하였다. TEM분석결과 육방정으로만 구성된 박막은 비정질상으로 이루어졌으며, 입방정과 육방정의 혼합상의 경우는 비정질기지상에 수십 nanometer크기의 입방정입자가 분산된 구조를 하고 있었다.

• 한국표면공학회지
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• 제31권5호
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• pp.266-277
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• 1998

The effects of $H_2S$ gas ratio, temperature and time on the case depth, hardness, and sulfide and nitride formation on the surface of sulfnitrided SCM440 steel have been studied by micro-pulse plasma technique. The thickness of compound layer of sulfide and nitride increased with the increase of time, temperautre and $H_2S$ gas ratio. But surface hardness decreased with the increase of soft sulfide layer because the hard nitride layer formed beneath the sulfide. The thickness of sulfide layer was about 10$\mu\textrm{m}$ abpve 0.0088% of $H_2S$ gas. The highest surface hardness of the compound layer was Hv835 at $530^{\circ}C$, 1hr and 0.06% of $H_2S$ gas. X-ray diffraction indicated that the surface products were $Fe_{1_x}S$, $Fe_{2.5}N$ and $Fe_4N$. It was confirmed by EPMA that sulfide only existed in the surface.

• 한국재료학회지
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• 제30권4호
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• pp.169-175
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• 2020

Silicon nitride thin films are deposited by RF (13.57 MHz) magnetron sputtering process using a Si (99.999 %) target and with different ratios of Ar/N₂ sputtering gas mixture. Corning G type glass is used as substrate. The vacuum atmosphere, RF source power, deposit time and temperature of substrate of the sputtering process are maintained consistently at 2 ~ 3 × 10^-3 torr, 30 sccm, 100 watt, 20 min. and room temperature, respectively. Cross sectional views and surface morphology of the deposited thin films are observed by field emission scanning electron microscope, atomic force microscope and X-ray photoelectron spectroscopy. The hardness values are determined by nano-indentation measurement. The thickness of the deposited films is approximately within the range of 88 nm ~ 200 nm. As the amount of N₂ gas in the Ar:N₂ gas mixture increases, the thickness of the films decreases. AFM observation reveals that film deposited at high Ar:N₂ gas ratio and large amount of N₂ gas has a very irregular surface morphology, even though it has a low RMS value. The hardness value of the deposited films made with ratio of Ar:N₂=9:1 display the highest value. The XPS spectrum indicates that the deposited film is assigned to non-stoichiometric silicon nitride and the transmittance of the glass with deposited SiO₂-Si_xN_y thin film is satisfactory at 97 %.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.725-730
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• 1996

The key process in silicon surface micromachining is the selective etching of a sacrificial layer to release the silicon microstructure. The newly developed anhydrous HF/$CH_3$OH gas phase etching of TEOS (teraethylorthosilicate) sacrificial layers onto the polysilicon and the nitride substrates was employed to release the polysilicon microstructures. A residual product after TEOS etching onto the nitride substrate was observed on the surface, since a SiOxNy layer is formed on the TEOS/nitride interface. The polysilicon microstructures are stuck to the underlying substrate because SiOxNy layer does not vaporize. We found that the only sacrificial etching without any residual product and stiction is TEOS etching onto the polysilicon substrate.

• 한국세라믹학회지
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• 제37권1호
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• pp.44-49
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• 2000

Silicon nitride powders, were synthesized by the vapor phase reaction using SiH4-NH3 gaseous mixture. The reaction temperature, ratio of NH3 to SiH4 gas and the overall gas quantity were varied. The synthesized powders were characterized using X-ray, TEM, FT-IR and EA. The synthesized silicon nitride powders were in amorphous state, and the average particle size was about 100nm. TEM analysis revealed that the particle size decreased with increasing reaction temperature and gas flow quantity. As-received amorphous powders were annealed in nitrogen atmosphere at 140$0^{\circ}C$ for 2h, then the powders were completely crystallized at 0.2 ratio of NH3 to SiH4.