• Journal of the Korean Vacuum Society
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• v.5 no.4
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• pp.359-364
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• 1996

$SrTiO_3$ thin films were deposited on Pt/Ti/$SiO_2$/Si substrates at low temperatures below $300^{\circ}C$ by r.f. magnetron sputtering. The materials and the electrical properties of the deposited films were investigated with controlling deposition parameters such as substrate temperature(T_s) and positive substrate d.c. bias voltage. Stoichiometric $SrTiO_3$ films were obtained at Ts of $300^{\circ}C$, but Sr content in the film was less than that of a target when Ts was lower than $300^{\circ}C$, resulting in poor electrical properties. By introducing a positive substrate d.c. bias during deposition, the crystallinity and the dielectric properties of the films were markedly improved. 400 nm thick $SrTiO_3$, films deposited at $300^{\circ}C$ with a positive substrate d.c. bias of 20V showed a columnar structure with <211> crystallographic direction and a dielectric constant of 98.

• Korean Journal of Materials Research
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• v.4 no.2
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• pp.143-151
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• 1994

On PT/Ti/Si substrates, PZT thln fllms are deposited at $300^{\circ}C$ by rf magnetron sputtering uslng a $(PbZr_{52}, Ti_{48})O_{3}$ composltc cerarnlc target. To abtaln, the stable phase, perovskltc structure, furnace annealmg techmque had been cmplo:~d In PbO amb~ent for the $550^{\circ}C$-$750^{\circ}C$ temperature ranges. On Pt(250$\AA$)/Ti(500$\AA$)/Si, Pt(1000)$\AA$/Ti(500$\AA$)/Si substrates, effects of Ti layer and Pt thickness are studled. Though thickness of the Pt layer 1s 1000$\AA$). oxygen diffusion is not prevented and accelerated by Ti layer actlng for oxygen sink sites durmg furnace annealing. The upper TI layer 1s transformed Into TIOX by oxyen dlffuslon and lower Ti layer Into silicide with in-diffused Pt. The formation of TiOx layer seems to affect the orlentatton of the PZT layer. Furnace annealed f~lm shows ferroelectr~c and electrical properties wth a remanent polarlzation of 3.3$\mu A /\textrm{cm}^2$, , coerclve fleld of 0.15MV/cm, a=571 (10kHz), leakage current 32.65$\mu A /\textrm{cm}^2$, , breakdown voltage of 0.4OMV/cm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.521-524
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• 2001

In this letter. we report on the investigation of Ti. Pt/Si/Ti Ohmic contacts to p-type 4H-SiC. The contacts were formed by a 2-step vacuum annealing at $500^{\circ}C$ for 1h. $950^{\circ}C$ for 10 min respectively. The contact resistances were measured using the transmission line model method. which resulted in specific contact resistivities in the $3.5{\times}10^{-3}$ and $6.2{\times}10^{-4}ohm/cm^{2}$, and the physical properties of the contacts were examined using x-ray diffraction. microscopy. AES(auger electron spectroscopy). AES analysis has shown that, at this anneal temperature, there was a intermixing of the Ti and Si. migration of into SiC. Overlayer of Pt had the effect of decreasing the specific contact resistivity and improving the surface morphology of the annealed contact.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.3
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• pp.7-11
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• 2000

The low-voltage driven $SrTiO_3$ceramic varistor device was fabricated from $SrTiO_3$ powders prepared by co-precipitation method with $CuO-SiO_2$additives. Compare with conventional process, this process has advantages such as the reduction of the sintering temperature of $SrTiO_3$ ceramics by 100-$150^{\circ}C$ and the simplification of processing procedure. The non-linear coefficient value ($\alpha$) of the varistor showed 8.47 when it was sintered at $1350^{\circ}C$ for 2 h with 5 wt% additives in reducing atmosphere of 5% $H_2/N_2$ mixed gas. The low-voltage driven $SrTiO_3$ceramic varistor was obtained which has a breakdown voltage as low as 7 V.

• Journal of the Korean Ceramic Society
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• v.33 no.12
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• pp.1301-1310
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• 1996

Generally it requires high sintering temperatures more than 135$0^{\circ}C$ to make semiconductive BaTiO3 ceramics. Also it is very difficult to achieve a homogeneous mixing in solid-state reaction method. Therefore the liquid phase distributed to non-uniform dilute the characteristics of PTCR. In order to improve the uniformity this study is used the sol-gel coating method. Using this method we studied the new manufacturing process that had a high reproducibility and mass production capability. Tetraethyl orthosilicate (TEOS) was used as a source of Si. The semiconductive BaTiO3 ceramics which was produced by sol-gel method for the SiO2 addition and sintered between 124$0^{\circ}C$ and 130$0^{\circ}C$ showed almost same resistivity at room temperature among 125$0^{\circ}C$ and 130$0^{\circ}C$. As the results We could be sintered the semiconducting BaTiO3 ceramics at lower temperature even at 125$0^{\circ}C$ maintaining the same specific resistivity ratio ($\rho$max/$\rho$min) at 130$0^{\circ}C$. The specific resistivity both below and above the Curie temperature were increased by slow cooling and the steepness of the plots in the reasion of transition from low to high resistance increased as the cooling rate decreased.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.3
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• pp.205-210
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• 2000

Lead titanate thin films were fabricated on Si(100) wafer and ITO-coated glass substrates by metal organic chemical vapor deposition using ultrasonic spraying. When the ratio (Ti/Pb) of starting materials was 1.2, the films deposited on Si wafer had a single perovskite phase. The films deposited on ITO-coated glass had higher growth rate than that on Si wafer. As deposition temperature was increased from $530^{\circ}C$ to $570^{\circ}C$, dielectric constant was increased due to the increase of crystallinity and grain size. At $570^{\circ}C$, dielectric constant and dielectric loss of the films were 205 and 0.016, respectively. When the deposition temperature is higher than $600^{\circ}C$, dielectric constant was decreased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.521-524
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• 2001

In this letter, we report on the investigation of Ti, Pt/Si/Ti Ohmic contacts to p-type 4H-SiC. The contacts were formed by a 2-step vacuum annealing at 500$^{\circ}C$ for 1h, 950$^{\circ}C$ for 10 min respectively. The contact resistances were measured using the transmission line model method, which resulted in specific contact resistivities in the 3.5x10$\^$-3/ and 6.2x10$\^$-4/ ohm/$\textrm{cm}^2$, and the physical properties of the contacts were examined using x-ray diffraction, microscopy, AES(auger electron spectroscopy). AES analysis has shown that, at this anneal temperature, there was a intermixing of the Ti and Si, migration of into SiC. Overlayer of Pt had the effect of decreasing the specific contact resistivity and improving the surface morphology of the annealed contact.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.4
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• pp.543-548
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• 2018

Ferroelectric $Bi_4Ti_3O_{12}$ films were deposited on $SrTiO_3(100)$ and Si(100) substrate by using conductive $SrRuO_3$ films as underlayer, and their ferroelectric and electrical properties were investigated depending on crystal structure and orientation. C-axis oriented $Bi_4Ti_3O_{12}$ films were grown on well lattice-matched pseudo-cubic $SrRuO_3$ films deposited on $SrTiO_3(100)$ substrate, while random-oriented polycrystalline $Bi_4Ti_3O_{12}$ films were grown on $SrRuO_3$ films deposited on Si(100) substrate. The random-oriented polycrystalline film showed a good ferroelectric hysteresis property with remanent polarization ($P_r$) of $9.4{\mu}C/cm^2$ and coercive field ($E_c$) of 84.9 kV/cm, while the c-axis oriented film showed $P_r=0.64{\mu}C/cm^2$ and $E_c=47kV/cm$ in polarizaion vs electric field curve. The c-axis oriented $Bi_4Ti_3O_{12}$ film showed a dielectric constant of about 150 and lower thickness dependence in dielectric constant compared to the random-oriented film. Furthermore, the c-axis oriented $Bi_4Ti_3O_{12}$ film showed leakage current lower than that of the polycrystalline film. The difference of ferroelectric properties in two films was explained from the viewpoint of depolarization effect due to orientation of spontaneous polarization and layered crystal structure of bismuth-base ferroelectric oxide.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.131-132
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• 2015

$Ti_{0.26}Al_{0.16}Si_{0.01}N_{0.57}$ (at%) coatings were synthesized on stainless steel 304 by using arc ion plating systems (AIPS). Targets employed for the deposition were Ti, AlSi(67:33at%) and AlSi(82:18at%). The thickness of TiAlSiN coatings is $4{\mu}m$. The oxidation characteristics of the deposited coatings were studied by thermogravimetric analysis (TGA) in air between 800 and $900^{\circ}C$ for 75 hr. The oxide scale formed on the TiAlSiN coatings consisted of $rutile-TiO_2$ layer and ${\alpha}-Al_2O_3$. At $800^{\circ}C$, the coatings oxidized relatively slowly, and the scales were thin and adherent. When oxidized above $900^{\circ}C$, $TiO_2$ grew fast over the mixed oxide layer, and the oxide scale formed on TiAlSiN coatings was prone to spallation. Microstructural changes of the TiAlSiN coatings that occurred during high temperature oxidation were investigated by EPMA, XRD, SEM and TEM.

• Journal of the Korean Ceramic Society
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• v.41 no.8
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• pp.593-598
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• 2004

To make the all-solid-state lithium thin film battery having less than 1 fm in thickness, LiCoO$_2$ thin films were deposited on Pt/TiO$_2$/SiO$_2$/Si substrate as a function of Li/Co mole ratio and the deposition temperature by Pulsed Laser Deposition (PLD). Especially, LiCoO$_2$ thin films deposited at 50$0^{\circ}C$ with target of Li/Co=1.2 mole ratio show an initial discharge capacity of 53 $\mu$Ah/cm$^2$-$\mu$m and capacity retention of 67.6％. The microstructural and electrochemical properies of (Li, La)TiO3 thin films grown on LiCoO$_2$Pt/TiO$_2$/SiO$_2$/Si structures by Pulsed Laser Deposition (PLD) were investigated at various deposition temperatures. The thin films grown at 10$0^{\circ}C$ show an initial discharge capacity of approximately 51 $\mu$Ah/cm$^2$-$\mu$m and moreover show excellent discharge capacity retention of 90％ after 100 cycles. An amorphous (Li, La)TiO$_3$ solid electrolyte is possible for application to solid electrolyte for all-solid-state lithium thin film battery below 1 $\mu$m.