• E2M - 전기 전자와 첨단 소재
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• 제10권6호
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• pp.541-547
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• 1997

(Pb$_{1-x}$ La$_{x}$)Ti$_{1-x}$ $_4$O$_3$(x=0, 0.02, 0.04, 0.08) ceramic thin films were fabricated by Sol-Gel method. A stock solution of (Pb, La)TiO$_3$ with excess Pb 10 mol% was made and spin-coated on the Pt/Ti/SiO$_2$/Si substrate at 400rpm for 30 seconds. Coated specimens were dried on the hot-plate at 35$0^{\circ}C$ for 10 min and sintered at 500~75$0^{\circ}C$ for 1 hour. The dielectric constant, remanent polarization and coercive field of the PLT(6at.%) thin films sintered at $650^{\circ}C$ were 884, 13.95$\mu$C/$\textrm{cm}^2$ and 8.7kV/cm, respectively. Pyroelectric coefficient, figure of merit of pyroelectric current, voltage responsivity and detectivity of PLT(6at.%) thin films were 3.2$\times$10$^{-8}$ C/$\textrm{cm}^2$K, 1.02$\times$10$^{-8}$ C.cm/J, 2.9 $\times$10$^{-11}$ C.cm/J, 0.29$\times$10$^{-8}$ C.cm/J, respectively.ely.

• 한국재료학회지
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• 제16권12호
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• pp.766-770
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• 2006

The frictional behavior of oxide films on top of the plasma nitrocarburized compound layers was investigated in terms of post-oxidation treatment temperatures. The post-oxidation treatment at both temperatures($400^{\circ}C,\;500^{\circ}C$) produced magnetite($Fe_3O_4$) films which led to a significant enhancement in corrosion resistance. However, this process did not result in any improvement in frictional behavior of the nitrocarburized surface. The wear mechanisms were governed predominantly by the abrasive action of the slider on the surface irrespective of the counterface material(SiC and Bearing steel). When the specimen was sliding against a SiC counterface, the oxide films were destroyed during the early stage of the sliding process and the wear debris of the oxide film at the sliding track had a great influence on the friction coefficient. On the other hand, when sliding against a bearing steel counterface, the slider was mainly worn out due to the much higher hardness of the surface hardened layer. The fluctuation of the friction coefficient of $400^{\circ}C$-oxidized/ nitrocarburized specimen is much severer than that of $500^{\circ}C$ specimen, due to the less amount of wear debris.

• 한국세라믹학회지
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• 제30권11호
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• pp.897-904
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• 1993

CdS doped SiO2 glass coating films which are good candidates for the nonlinear optical materials were prepared by the Sol-Gel method. TEOS, C2H5OH, H2O and HCl were used as starting materials to obtain SiO2 matrix solutions. Then Cd(NO3)2.2H2O and CS(NH2)2 were dissolved into the SiO2 matrix solutions. Coating was performed several times in order to increase the thickness of coated film by the dip-coating method. Then heat treatments were carried out to control the size of CdS microcrystals doped in SiO2 glass matrix with respect to temperatures and times. CdS-doped SiO2 transparent coating films were successfully obtained. CdS crystals were changed from cubic to hexagonal type about $600^{\circ}C$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.718-721
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• 2004

The $(Sr_{0.9}Ca_{0.1})TiO_3$(SCT) thin films are deposited on Pt-coated electrode$(Pt/TiN/SiO_2/Si)$ using RF sputtering method at various substrate temperature. The optimum conditions of RF power and $Ar/O_2$ ratio were 140[W] and 80/20, respectively. Deposition rate of SCT thin films was about $18.75[{\AA}/min]$. The crystallinity of SCT thin films were increased with increase of substrate temperature in the temperature range of $100\sim500[^{\circ}C]$. The dielectric constant of SCT thin films were increased with the increase of substrate temperature, and changed almost linearly in temperature ranges of $-80\sim+190[^{\circ}C]$. The current-voltage characteristics of SCT thin films showed the increasing leakage current as the substrate temperature increases.

• Transactions on Electrical and Electronic Materials
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• 제14권3호
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• pp.130-132
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• 2013

$Bi_{3.25}La_{0.75}Ti_3O_{12}$(BLT) thin films were prepared on the Pt(150 nm)/Ti(50 nm)/$SiO_2$/Si substrate using the rf magnetron sputtering method. The BLT thin films were annealed at temperatures ranging from $600^{\circ}C$ to $750^{\circ}C$ using the rapid thermal annealing. The structure and surface morphology of the thin films were characterized by x-ray diffraction and field emission scanning electron microscopy. The hysteresis loop of the BLT thin films showed that the remanent polarization (2Pr) of the film annealed at $700^{\circ}C$ was 10.92 ${\mu}C/cm^2$. The fatigue characteristic of the BLT thin film annealed at $700^{\circ}C$ was shown change polarization up to $1.2{\times}10^9$ switching cycles. We confirmed the excellent remnant polarization (Pr) and fatigue properties compared with other fabrication methods and suggested a good method for BLT thin films fabrications.

• 한국세라믹학회지
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• 제30권1호
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• pp.17-24
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• 1993

Sol-gel spin-coating technique was used to produce Nb2O5 thin films on silicon substrates from Nb(OC2H5)5 precursor. The films were heat-treated at temperatures between $600^{\circ}C$ and 100$0^{\circ}C$ in oxygen atmosphere and their crystalline phases, chemical states, and dielectric characteristics were investigated by X-ray diffractometry (XRD), Auger electron spectroscopy (AES), and C-V measurements, respectively. After 1 hour heat-treatment at 80$0^{\circ}C$, T-type Nb2O5 was formed, and its chemical composition was homogeneous with no appreciable SiO2 oxide at interfaces between the films and substrates. The films heat-treated at temperatures between $600^{\circ}C$ and 80$0^{\circ}C$ exhibit dielectric constant of less than 20 while the films heat treated at 100$0^{\circ}C$ show dielectric constant of 28.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2006년도 추계학술대회 발표 논문집
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• pp.10-13
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• 2006

This paper describes on the fabrication and characteristics of a 3C-SiC (Silicon Carbide) micro pressure sensor for harsh environment applications. The implemented micro pressure sensor used 3C-SiC thin-films heteroepitaxially grown on SOI (Si-on-insulator) structures. This sensor takes advantages of the good mechanical properties of Si as diaphragms fabricated by D-RIE technology and temperature properties of 3C-SiC piezoresistors. The fabricated pressure sensors were tasted at temperature up to $250^{\circ}C$ and indicated a sensitivity of 0.46 mV/V*bar at room temperature and 0.28 mV/V*bar at $250^{\circ}C$. The fabricated 3C-Sic/SOI pressure sensor presents a high-sensitivity and excel lent temperature stability.

• 한국세라믹학회지
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• 제35권10호
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• pp.1107-1112
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• 1998

We could obtan c-axis oriented $SrBi_2$$Ta_2$$O_9$ thin films on usual Pt(111)/Ti/$SiO_2$/Si(100) substrate using a r. f. magnetron sputtering technique. According to the increase of sputtering pressure from 250 to 300 mTorr the Bi content and degree of the c-a xis preferred orientation of $SrBi_2$$Ta_2$$O_9$ thin films were increased. By controlling Bi(or $Bi_2O_3$) loss from $SrBi_2$$Ta_2$$O_9$ thin films during post annealing and by inserting $Bi_2O_3$ layer in $SrBi_2$$Ta_2$$O_9$ thin films the effect of Bi content on the c-axis oriented growth of $SrBi_2$$Ta_2$$O_9$ thin films could be investigated without the effect of sputtering pressure. The degree of the c-axis preferred orientation of $SrBi_2$$Ta_2$$O_9$ thin films was increased with increasing with increasing Bi content by control of Bi(or $Bi_2O_3$) loss of $SrBi_2$$Ta_2$$O_9$ thin films. But the c-axis oriented growth of $SrBi_2$$Ta_2$$O_9$ thin films disappeared by the inserting of $Bi_2O_3$ lay-er in $SrBi_2$$Ta_2$$O_9$ thin films.

• 한국재료학회지
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• 제14권11호
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• pp.780-785
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• 2004

The degradation mechanism of soft magnetic properties of $Fe-Hf-N/Cr/SiO_2$ thin films reacted with a bonding glass was investigated. When $Fe-Hf-N/Cr/SiO_2$ films were annealed under $600^{\circ}C$ without the bonding glass, the compositions and the soft magnetic properties of Fe-Hf-N layers were not changed. However, after reaction with the bonding glass at $550^{\circ}C$, the soft magnetic properties of the film were degraded. At $600^{\circ}C$, the saturation magnetization of the reacted film decreased to 13.5 kG, and its coercivity increased to 4 Oe, and its effective permeability decreased to 700. It was founded that O diffused from the glass into the Fe-Hf-N layers during the reaction and generated $HfO_2$ phases. It was considered that the soft magnetic properties of the $Fe-Hf-N/Cr/SiO_2$ films reacted with the bonding glass were primarily degraded by the formation of the Fe-Hf-O-N layer of which the Fe content was below 60 $at\%$, and secondarily degraded by the Fe-Hf-O-N layer above 70 $at\%$.

• 한국전기전자재료학회논문지
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• 제11권9호
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• pp.711-717
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• 1998

BST(70/30) and BST(50/50) thin films were prepared by Sol-Gel method and studied about the microstructural and dielectric properties with Pt and ITO bottom electrodes. The stock solution was synthesized and spin coated on the Pt/Ti$SiO_2$/Si and Indium Tin Oxide(ITO)/ glass substrate. the coated films were dries at 350$^{\circ}C$ for 10 minutes and annealed at $750^{\circ}C$ for 1 hour for the crystallization. The thin films coated on ITO substrate were crystallized easily and the packing density and roughness of surface were better that those of films coated on Pt substrates. In the BST(50/50) composition the structural properties were similar to the BST(70/30) composition and grain size were decreased with increasing the contents of Sr. The dielectric constant was higher in the BST(50/50) composition compared with the BST(70/30) composition. Using the ITO substrate, the dielectric constant was higher than the Pt substrate while the dielectric loss was showed a reverse trend. The dielectric constant with and increase of temperature was decreased slowly.