• Journal of the Semiconductor & Display Technology
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• v.6 no.3
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• pp.19-23
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• 2007

The NiSi is very promising candidate for the metallization in 45 nm CMOS process such as FUSI(fully silicided) gate and source/drain contact because it exhibits non-size dependent resistance, low silicon consumption and mid-gap workfunction. Ni film was first deposited by using ALD (atomic layer deposition) technique with Bis-Ni precursor and $H_2$ reactant gas at $220^{\circ}C$ with deposition rate of $1.25\;{\AA}/cycle$. The as-deposited Ni film exhibited a sheet resistance of $5\;{\Omega}/{\square}$. RTP (repaid thermal process) was then performed by varying temperature from $400^{\circ}C$ to $900^{\circ}C$ in $N_2$ ambient for the formation of NiSi. The process temperature window for the formation of low-resistance NiSi was estimated from $600^{\circ}C$ to $800^{\circ}C$ and from $700^{\circ}C$ to $800^{\circ}C$ with and without Ti capping layer. The respective sheet resistance of the films was changed to $2.5\;{\Omega}/{\square}$ and $3\;{\Omega}/{\square}$ after silicidation. This is because Ti capping layer increases reaction between Ni and Si and suppresses the oxidation and impurity incorporation into Ni film during silicidation process. The NiSi films were treated by additional thermal stress in a resistively heated furnace for test of thermal stability, showing that the film heat-treated at $800^{\circ}C$ was more stable than that at $700^{\circ}C$ due to better crystallinity.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.316-322
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• 2006

The current study evaluated the technical feasibility of the application of $TiO_2$ photocatalysis for the removal of nocotine which has well known as a representative material of environmental tobacco smoke(ETS). Four different preliminary experiments were performed for the evaluation of nicotine removal using photocatalyst-coated construction materials. The photocatalytic removal of nicotine was investigated for five parameters: dry condition of coating tiles, type of coating sol, number of coatings, relative humidity(RH), and input concentrations. Prior to performing the parameter tests, adsorption of nicotine onto the current experimental system was surveyed. All the variables tested in the present study exhibited to influence the photocatalytic decomposition of Nicotine. A dry condition of high temperature and short dry period presented higher photocatalytic oxidation(PCO) efficiency compared to that of low temperature and long dry period. ST-KO3 sol showed higher decomposition efficiency than E-T Sol. The PCO efficiency increased as the number of coating increased. High humidity and low input concentrations exhibited higher PCO efficiency. Consequently, it is noted that the five parameters tested in the present study should be considered for the application of photocatalyst-coated construction materials in cleaning nicotine in ETS.

• Korean Journal of Materials Research
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• v.11 no.3
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• pp.236-242
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• 2001

HfN/Si$_3$N$_4$and NbN/Si$_3$N$_4$ multilayer coatings were deposited onto a high speed tool steel substrate by reactive sputtering and their mechanical properties were evaluated in terms of the dependence of hardness and adhesion strength on the sputter deposition process parameters. The hardnesses of both HfN/Si$_3$N$_4$and NbN/Si$_3$N$_4$ multiplayer coatings increase up to the flux ratio of 0.4 but nearly do not change after that as the $N_2$/Ar flux ratio in nitride sputter deposition increases. The hardnesses of both multiplayer coatings nearly do not change with annealing at low temperatures but decrease owing to oxidation with annealing at a high temperature like 80$0^{\circ}C$ after depositing the layers by sputtering. Post-annealing at low temperatures increases the adhesion strength of the multilayers. but high temperature annealing is not desirable since it decreases the adhesion strength besides the hardness deterioration.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.5
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• pp.398-402
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• 2012

Synthesis of $Li_2MnSiO_4$ was attempted by the conventional solid-state reaction method, and the phase formation behavior according to the change of the calcination condition was investigated. When the mixture of the three source materials, $Li_2O$, MnO and $SiO_2$ powders, were used for calcination in air, it was difficult to develop the $Li_2MnSiO_4$ phase because the oxidation number of $Mn^{2+}$ could not be maintained. Therefore, two-step calcination was applied: $Li_2SiO_3$ was made from $Li_2O$ and $SiO_2$ at the first step, and $Li_2MnSiO_4$ was synthesized from $Li_2SiO_3$ and MnO at the second step. It was easy to make $Li_2MnSiO_3$ from $Li_2O$ and $SiO_2$. $Li_2MnSiO_4$ single phase was developed by the calcination at $900^{\circ}C$ for 24 hr in Ar atmosphere as the oxidation of $Mn^{2+}$ was prevented. However, the $Li_2MnSiO_4$ was ${\gamma}-Li_2MnSiO_4$, one of the polymorph of $Li_2MnSiO_4$, which could not be used as the cathode materials in Li-ion batteries. By applying the additional low temperature annealing at $400^{\circ}C$, the single phase ${\beta}-Li_2MnSiO_4$ powder was synthesized successfully through the phase transition from ${\gamma}$ to ${\beta}$ phase.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5357-5364
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• 2011

The objective of this study is development of carbon recycle technology which convert carbon dioxide captured from flue gas to carbon monoxide or carbon and reuse in industrial fields. Since carbon dioxide is very stable and difficult to decompose, metal oxide was used as activation agent for the decomposition of carbon dioxide at low temperature. Metal oxides which convert $CO_2$ to CO or carbon were prepared using Ba-ferrite by solid and hydrothermal synthesis. TPR/TPO and TGA were used in this study. The results of TPR by H2 and TPO by $CO_2$ showed that Ba-ferrite powders synthesized by hydrothermal method were better than those by solid method. TGA showed contrary results that reduction of Ba-ferrite powders synthesized using solid method by $H_2$ was 21.96 wt%, oxidation by $CO_2$ was 21.24 wt% and 96.72 wt% of $CO_2$ decomposition efficiency showing excellent oxidation-reduction characteristics at $500^{\circ}C$.

• Journal of Sensor Science and Technology
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• v.8 no.2
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• pp.115-123
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• 1999

A micro-gas sensor with heater and sensing electrode on the same plane was fabricated on phosphosilicate glass(PSG, 800nm)/$Si_3N_4$ (150nm) dielectric membrane. PSG film was provided by atmospheric pressure chemical vapor deposition(APCVD), and $Si_3N_4$ film by low pressure chemical vapor deposition (LPCVD). Total area of the fabricated device was $3.78{\times}3.78mm^2$. The area of diaphragm was $1.5{\times}1.5mm^2$, and that of the sensing layer was $0.24{\times}0.24mm^2$. Finite-element simulation was employed to estimate temperature distribution for a square-shaped diaphragm. The power consumption of Pt heater was about 85mW at $350^{\circ}C$. Tin thin films were deposited on the silicon substrate by thermal evaporation at room temperature and $232^{\circ}C$, and tin oxide films($SnO_2$) were prepared by thermal oxidation of the metallic tin films at $650^{\circ}C$ for 3 hours in oxygen ambient. The film analyses were carried out by SEM and XRD techniques. Effects of humidity and ambient temperature on the resistance of the sensing layer were found to be negligible. The fabricated micro-gas sensor exhibited high sensitivity to butane gas.

• Korean Journal of Materials Research
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• v.22 no.4
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• pp.202-206
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• 2012

$CoSi_2$ was formed through annealing of atomic layer deposition Co thin films. Co ALD was carried out using bis(N,N'-diisopropylacetamidinato) cobalt ($Co(iPr-AMD)_2$) as a precursor and $NH_3$ as a reactant; this reaction produced a highly conformal Co film with low resistivity ($50\;{\mu}{\Omega}cm$). To prevent oxygen contamination, $ex-situ$ sputtered Ti and $in-situ$ ALD Ru were used as capping layers, and the silicide formation prepared by rapid thermal annealing (RTA) was used for comparison. Ru ALD was carried out with (Dimethylcyclopendienyl)(Ethylcyclopentadienyl) Ruthenium ((DMPD)(EtCp)Ru) and $O_2$ as a precursor and reactant, respectively; the resulting material has good conformality of as much as 90% in structure of high aspect ratio. X-ray diffraction showed that $CoSi_2$ was in a poly-crystalline state and formed at over $800^{\circ}C$ of annealing temperature for both cases. To investigate the as-deposited and annealed sample with each capping layer, high resolution scanning transmission electron microscopy (STEM) was employed with electron energy loss spectroscopy (EELS). After annealing, in the case of the Ti capping layer, $CoSi_2$ about 40 nm thick was formed while the $SiO_x$ interlayer, which is the native oxide, became thinner due to oxygen scavenging property of Ti. Although Si diffusion toward the outside occurred in the Ru capping layer case, and the Ru layer was not as good as the sputtered Ti layer, in terms of the lack of scavenging oxygen, the Ru layer prepared by the ALD process, with high conformality, acted as a capping layer, resulting in the prevention of oxidation and the formation of $CoSi_2$.

• Clean Technology
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• v.7 no.1
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• pp.65-74
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• 2001

Modified dip-coating method 8.3 times shorten in solution volume-coated and 83.3 times in coating time than existing dip-coating method. Coating weight increased nearly 2~3 times. So modified dip-coating method is evaluated that it is economic and has a efficiency. When we make an experiment in coated $LaCoO_3$ on ceramic monolith in modified dip-coating method which use 2 coating applications with relative viscosity $0.006202kg{\cdot}m/sec$, it showed a superior reaction at 88.56mg per ceramic unit gram in NO-CO reaction(optimum coating amount). When we make an experiment in the same size of ceramic filter cell with different conditions 100, 200cell per square inch, the result in low temperature($200^{\circ}C{\sim}350^{\circ}C$), 200cell3 per square inch is 6~23% higher in NO reduction and 11% in CO oxidation than 100cell per square inch. It is because the more the number of cells in the ceramic filter increase, the more catalytic surface area is expanded.

• Journal of IKEEE
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• v.20 no.2
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• pp.205-208
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• 2016

In this paper, different types of touch screen silver pastes for bonding in conductive pattern formed over the ito film by bonding each sample of 5 was dried. The dry conditions, the oxidation of the ito film is a condition that does not occur. Reliability testing constant temp and humidity, cold-hot impact test is in progress. Each test will check the status of five sheets conductive pattern bonding. Conductive pattern bonding, after each 240,480,615 hours to check the status of silver pattern bonding. Reliability testing these through different silver pastes can see that the change in the adhesion and conductivity deterioration of the quality can be prevented, and reliability testing low temperature curing from the surface of silver pastes that can come as soon as the discoloration was unknown.

• Journal of Sensor Science and Technology
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• v.8 no.1
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• pp.32-37
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• 1999

A capacitance-type humidity sensor with mesa structure in which porous silicon layer is used as humidity-sensing material is developed and its humidity sensing properties are measured. This sensor has a structure where two electrodes are set on the up-side of the wafer against the past typical structure having these electrodes on the up and down-side of the wafer. Therefore, the sensor can be fabricated monolithically to be more compatible with the IC process technology, and is possible to detect more correct output capacitance by removing the effect of the parasitic capacitance from the bottom layer and other junctions. To do this, the sensor was fabricated using process such as localized formation of porous silicon, oxidation of porous silicon layer, and etching of oxidized porous silicon layer. From the completed samples, the dependence of capacitance on the relative humidity of 55 to 90% more was measured at room temperature. As the result, the measured capacitance increased monotonously higher at the low frequency of 120 Hz, where the capacitance was observed to increase over 300%.