• 정보저장시스템학회논문집
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• 제3권3호
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• pp.129-134
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• 2007

Boron nitride (BN) is a highly attractive material for wear resistant applications of mechanical components. BN is super hard and it is the second hardest of all known materials. It also has a high thermal stability, high abrasive wear resistance, and in contrast to diamond, BN does not react with ferrous materials. The motivation of this work is to investigate the tribological properties of BN for potential applications in ultra-precision components for data storage, printing, and other precision devices. In this work, the wear characteristics of BN thin films deposited on DLC or Ti buffer layer with silicon substrate using RF-magnetron sputtering technique were analyzed. Wear tests were conducted by using a pin-on-disk type tester and the wear tracks were measured with a surface profiler. Experimental results showed that wear characteristics were dependent on the sputtering conditions and buffer layer. Particularly, BN coated on DLC layer showed better wear resistant behavior. The range of the wear rates for the BN films tested in this work was about 20 to $100{\mu}m^3$/cycle.

• 한국세라믹학회지
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• 제52권6호
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• pp.435-440
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• 2015

It is a challenge from an industrial point of view to fabricate silicon nitride substrates with high thermal conductivity and good mechanical properties for power devices from high-purity Si scrap powder by means of thick film processes such as tape casting. We characterize the residual carbon and oxygen content after the binder burnout followed by nitridation as a function of the temperature in the temperature range of $300^{\circ}C-700^{\circ}C$ and the atmosphere in a green tape sample which consists of high-purity Si powder and polymer binders such as polyvinyl butyral and dioctyl phthalate. The optimum condition of binder burnout is suggested in terms of the binder removal temperature and atmosphere. If considering nitridation, the burnout of the organic binder in air compared to that in a nitrogen atmosphere could offer an advantage when fabricating reaction-bonded $Si_3N_4$ substrates for power devices to enable low carbon and oxygen contents in green tape samples.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.729-732
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• 2006

The effect of stress match between silicon nitride ($SiN_2$) and hydrogenated amorphous silicon (a-Si:H) layers on the electrical characteristics of thin-film transistors (TFTs) has been investigated. The result shows that modifying the deposition conditions of a Si:H and $SiN_2$ thin films can reduce the stress mismatch at a-Si:H/SiNx interface. Moreover, for best a-Si:H TFT characteristics, the internal stress of gate $SiN_2$ layer with slightly nitrogen-rich should be matched with that of a-Si:H channel layer. The ON current, field-effect mobility, and stability of TFTs can be enhanced by controlling the stress match between a-Si:H and gate insulator. The improvement of these characteristics appears to be due to both the decrease of the interface state density between the a-Si:H and SiNx layer, and the good dielectric quality of the bottom nitride layer.

• 센서학회지
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• 제14권5호
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• pp.343-349
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• 2005

Carbon nitride films were deposited on various substrates for humidity sensors with meshed electrode by reactive RF magnetron sputtering system. As the ratio of injected nitrogen was decreased, the sensitivity of sensor was increased. When the ratio of injected nitrogen was $50{\sim}70%$, the sample showed the best linearity. The sensor impedance changed from $95.4{\;}k{\Omega}$ to $2.1{\;}k{\Omega}$ in a relative humidity range of 5 % to 95 %. The humidity sensors based on silicon wafer revealed higher lineality and faster response than those of alumina or quartz substrates. The adsorption saturation time of the sample was about 80 sec, and its desorption time was about 90 sec.

• 전자공학회논문지D
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• 제36D권7호
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• pp.17-25
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• 1999

PECVD 법을 이용하여 Tungsten Nitride($WN_x$) 박막을 $WSi_3N_4$ 기판위에 형성하였다. $WN_x$ 박막은 기관온도, 가스의 유량, rf power 등의 공정변수를 변화시키면서 형성되었고, 서로 다른 질소원으로 $NH_3$와 $N_2$를 각각 사용하여 박막의 특성을 조사하였다. $WN_x$ 막 내의 질소함량은 $NH_3$와 $N_2$의 유량에 따라 0~45% 정도로 변화하였으며, $NH_3$를 사용하였을 때, 최고 160nm/min의 높은 성장률을 나타내었다. $WSi_3N_4$ 기판 위에서는 TiN이나 Si 위에서보다 높은 성장률을 나타내었다. $WN_x$ 박막의 순도를 AES로 측정해 본 결과 $NH_3$를 사용했을 때 고순도의 박막을 얻을 수 있었다. XRD 분석으로 순수한 다결정의 W가 비정질의 $WN_x$로 변화되는 것을 알 수 있었으며, 이것은 $WN_x$가 식각 공정시 미세 패턴 형성이 W보다 유리할 것이라는 것을 보여준다. TiN, NiCr, Al 등의 다양한 기판 위에 형성해 본 결과 Al 위에서 최대 $1.6 {\mu}m$의 두꺼운 막이 형성되었다.

• 한국전기전자재료학회논문지
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• 제18권7호
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• pp.662-666
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• 2005

Silicon nitride $(SiN_x)$ film is a promising material for anti-reflection coating and passivation of multicrystalline silicon (me-Si) solar cells. In this work, a plasma-enhanced chemical vapor deposition (PECVD) system with batch-type reactor tube was used to prepare highly robust $SiN_x$ films for screen-printed mc-Si solar cells. The Gas flow ratio, $R=[SiH_4]/[NH_3]$, in a mixture of silane and ammonia was varied in the range of 0.0910.235 while maintaining the total flow rate of the process gases to 4,200 sccm. The refractive index of the $SiN_x$ film deposited with a gas flow ratio of 0.091 was measured to be 2.03 and increased to 2.37 as the gas flow ratio increased to 0.235. The highest efficiency of the cell was $14.99\%$ when the flow rate of $SiH_4$ was 350 sccm (R=0.091). Generally, we observed that the efficiency of the mc-Si solar cell decreased with increasing R. From the analysis of the reflectance and the quantum efficiency of the cell, the decrease in the efficiency was shown to originate mainly from an increase in the surface reflectance for a high flow rate of $SiH_4$ during the deposition of $SiN_x$ films.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.135-136
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• 2002

Molybdenum Nitrided (MoNx) films were deposited by DC planar magnetron sputtering. Silicon wafers and real nitrided stainless steel piston rings are employed as substrates. 12 different combinations of nitrogen and argon partial pressure, from 1:7 to 7:1, were applied to deposit MoNx films. X-ray diffraction (XRD) was used to determine the phase structures of films. When nitrogen vs. argon partial pressure is 1:7, the film is mainly $Mo_2N$ phase. With increase of nitrogen partial pressure, MoN phase emerges, but $Mo_2N$ phase still exists. Composition analysis with atomic emission spectrometry (AES) also agreed with this. The films have very high nanohardness (max 2400Hv) and good adhesion to the substrates.

• 한국전기전자재료학회논문지
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• 제11권1호
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• pp.33-40
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• 1998

The composite SiO$_2$/Si$_3$N$_4$/SiO$_2$(ONO) film formed by oxidation on nitride film has been widely studied as DRAM stacked capacitor multi-dielectric films. Load lock(L/L) LPCVD system by HF cleaning is used to improve electrical capacitance and to scale down of effective thickness for memory device, but is brings a new problem. Nitride film deposited using HF cleaning shows selective deposition on poly silicon and oxide regions of capacitor. This problem is avoidable by carpeting chemical oxide using $H_2O$$_2$cleaning before nitride deposition. In this paper, we study the limit of nitride thickness for abnormal oxidation and the initial deposition time for nitride deposition dependent on underlayer materials. We proposed an advanced fabrication process for stacked capacitor in order to avoid selective deposition problem and show the usefulness of nitride deposition using L/L LPCVD system by $H_2O$$_2$cleaning. The natural oxide thickness on polysilicon monitor after HF and $H_2O$$_2$cleaning are measured 3~4$\AA$, respectively. Two substrate materials have the different initial nitride deposition times. The initial deposition time for polysilicon is nearly zero, but initial deposition time for oxide is about 60seconds. However the deposition rate is constant after initial deposition time. The limit of nitride thickness for abnormal oxidation under the HF and $H_2O$$_2$cleaning method are 60$\AA$, 48$\AA$, respectively. The results obtained in this study are useful for developing ultra thin nitride fabrication of ONO scaling and for avoiding abnormal oxidation in stacked capacitor application.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.136.1-136.1
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• 2015

In the present study, UHF (320 MHz) in combination with RF (13.56 MHz) plasmas was used for the synthesis of hydrogenated silicon nitride (SiNx:H) films by PECVD process at low temperature. RF/UHF hybrid plasmas were maintained at a fixed pressure of 410 mTorr in the N2/SiH4 and N2/SiH4/NH3 atmospheres. To investigate the radical generation and plasma formation and their control for the growth of the film, plasma diagnostic tools like vacuum ultraviolet absorption spectroscopy (VUVAS), optical emission spectroscopy (OES), and RF compensated Langmuir probe (LP) were utilized. Utilization of RF/UHF hybrid plasmas enables very high plasma densities ~ 1011 cm-3 with low electron temperature. Measurements using VUVAS reveal the UHF source is quite effective in the dissociation of the N2 gas to generate more active atomic N. It results in the enhancement of the Si-N bond concentration in the film. Consequently, the deposition rate has been significantly improved up to 2nm/s for the high rate synthesis of highly transparent (up to 90 %) SiNx:H film. The films properties such as optical transmittance and chemical composition are investigated using different analysis tools.

• ETRI Journal
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• 제26권3호
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• pp.257-261
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• 2004

We grew amorphous SiCN films by pulsed laser deposition using mixed targets. The targets were fabricated by compacting a mixture of SiC and $SiC-{Si_3}{N_4}$ powders. We controlled the film stoichiometry by varying the mixing ratio of the target and the target-to-substrate distance. The mixing ratio of the target had a dominant effect on the film composition. We consider the structures of the SiCN films deposited using 30~70 wt.% SiC in the target to be an intermediate phase of SiC and $SiN_x$. This provides the possibility of growing homogeneous SiCN films with a mixed target at a moderate target-to-substrate distance.