• Journal of the Korean Ceramic Society
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• v.40 no.2
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• pp.184-190
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• 2003

$Sr_{0.9}Bi_{2.1}Ta_2O_9$thin films were deposited on $IrO_2$ electrode by spin coating method using photosensitive sol-gel solution. To ensure the UV-exposure effect on SBT thin films, UV irradiated films and non-UV irradiated films were analyzed by XRD, SEM. As a result, UV-irradiation on SBT thin films promoted grain growth of SBT compared with no UV irradiation. In case of the UV irradiated films annealed at$740{\circ}C$for 1 h in an oxygen ambient, the 2Pr value and Pr/Ps at${pm}5$V were$11.48{mu}C/cm^2$and 0.53, respectively. 2Pr values of the UV irradiated SBT thin films at$660-740{circ}C were approximately 12% higher than those of non-UV irradiated thin films.

• Journal of the Korean Vacuum Society
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• v.8 no.3A
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• pp.224-230
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• 1999

$SrBi_{2x}Ta_2O_9$ (SBT) thin films were prepared on platinized silicon substrates by MOD process, and their ferroelectric and leakage current characteristics were investigated. The grain size of the MOD derived SBT films increased with increasing the BI/Ta mole ration. Although the SBT films with x of 0.8~1.2 were composed of the equiaxed grains, the elongated grains were also observed for the SBT films with x of 1.4 and 1.6. The SBT film with x of 1.2 exhibited the optimum ferroelectric properties of 2PR : 9.79 $\muC/\textrm{cm}^2$ and Ec : 24.2kV/cm at applied voltage of 5V. The leakage current density of the SBT films increased with increasing the BI/Ta mole ratio. With post annealing process, 2Pr and $E_c$of the SBT film with x of 1.2 increases 11.3 $\muC/\textrm{cm}^2$ and 39.6kV/cm, respectively. decrement of the leakage current density by post annealing process increased remarkably with increasing the Bi/ta mole ratio, and the SBT film with x=1.6 exhibited the lowest leakage current density after post annealing process.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.3
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• pp.39-45
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• 1998

SrBi$_{2}$Ta$_{2}$O$_{9}$ (SBT) ferroelectric thin films for nonvolatile memory were prepared on Pt/Ti/SiO$_{2}$/Si and RuO$_{2}$/SiO$_{2}$/Si substrates by RF magnetron sputtering. The dependences of crystalline and electrical properties on the lower electrode type(Pt and RuO$_{2}$) and the annealing temperatures were investigated. SBT films regardless of their electrode types showed typeical Bi layered peroviskite crystal structures. The crystalline quality of as-deposited SBT films was improved by the rapid thermal annealing at 650.deg. C for 30 sec. The remanetn polarization of 2Pr (Pr+-Pr-) of the annealed SBT films deposited on Pt/Ti/SiO$_{2}$/Si substrates were about 11 .mu.C/cm$^{2}$ and 3 .mu.C/cm$^{2}$, respectively. The leakage currents at 3 V bias voltage were about 0.8 .mu.A/cm$^{2}$ for SBT/ Pt/Ti/SiO$_{2}$/Si and about 1 .mu.A/cm$^{2}$ for SBT/RuO$_{2}$/SiO$_{2}$/Si sample. SBT films annealed at 650 .deg. C showed no degradation in Pr values after 10$^{11}$ polarization switching cycles, indicating good fatigue properties. In addition, for SBT samples deposited on Pt/Ti/SiO$_{2}$/Si, Pr values increased to more than that of initial state, suggesting the increament of leakage current caused by repeated polarization.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.1
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• pp.1-5
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• 2013

In this paper, we investigated the etching characteristics of the TaN thin films and the surface reaction of TaN thin films after etching process. The etching characteristics of the TaN thin films were carried out using inductively coupled plasma (ICP). The etch rate and the selectivity of TaN to $SiO_2$ and TaN to PR were measured by varying the gas mixing ratio, RF power, DC-bias voltage, and process pressure in CF-based plasma. The surface reaction of TaN thin films were determined by x-ray photoelectron spectroscopy (XPS).

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.4
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• pp.185-194
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• 2006

A fungal strain of Trichoderma having strong chitinolytic activity was isolated from field soil enriched with crabshell for several years. Based on 5.8S rRNA, partial 18S, 28S rRNA genes, ITS1, ITS2 sequence analysis and morphological characteristics, the fungus was identified as Trichoderma asperellum and named as Trichoderma asperellum T-5 (TaT-5). The fungus released lytic enzymes such as chitinase and ${\beta}$-1, 3-glucanse, and produced six antifungal substances in chitin broth medium. To demonstrate the protective effect of TaT-5 against damping-off in cucumber plant caused by Rhizoctonia solani, TaT-5 culture broth (TA), chitin medium (CM) and distilled water (DW) were applied to each pot at 10 days after sowing, respectively. Then, the homogenized hyphae of R. solani were infected to each pot at 1 week after TaT-5 inoculation. During experimental period, fresh weight of shoot and root in cucumber plant more increased at TA treatment compared to other treatments. PR-proteins (${\beta}$-1, 3-glucanase and chitinase) activities in cucumber leaves markedly increased at CM and DW treatments, but the activity slightly increased and then decreased at TA treatment at 3 days after infection of R. solani. The activity of PR-proteins activities in cucumber roots at all treatments decreased with time where the degree of decrement was more alleviated at TA treatment than CM and DW. These results suggest that the lytic enzymes (chitinase and ${\beta}$-1, 3-glucanse) and antifungal substances produced by TaT-5 can reduce the pathogenic attack by R. solani in cucumber plants.

• Journal of the Korean institute of surface engineering
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• v.42 no.6
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• pp.251-255
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• 2009

In this study, the plasma etching of the TaN thin film with $O_2/BCl_3$/Ar gas chemistries was investigated. The equipment for the etching was an inductively coupled plasma (ICP) system. The etch rate of the TaN thin film and the selectivity of TaN to $SiO_2$ and PR was studied as a function of the process parameters, including the amount of $O_2$ added, an RF power, a DC-bias voltage and the process pressure. When the gas mixing ratio was $O_2$(3 sccm)/$BCl_3$(6 sccm)/Ar(14 sccm), with the other conditions fixed, the highest etch rate was obtained. As the RF power and the dc-bias voltage were increased, the etch rate of the TaN thin film was increased. X-ray photoelectron spectroscopy (XPS) was used to investigate the chemical states of the surface of the TaN thin film.

• Journal of the Korean Ceramic Society
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• v.40 no.1
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• pp.46-51
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• 2003

Ferroelectric $Sr_{0.7}Bi_{2.1}Ta_{2.0}O_9$ thin films with 200 nm thicknesses were deposited on $Pt/Ti/SiO_2/Si$ substrate by liquid delivery MOCVD process. In these experiments, $Sr(TMHD)_2{\cdot}pmdeta,\; Bi(ph)_3$ and $Ta(O^i/Pr)_4(TMHD)$ were used as precursors, which were dissolved in n-butyl acetate and pentamethyldiethylenetriamine. Substrate temperature and reactor pressure of this experiment was $570^{\circ}C$and 5 Torr, respectively. The remanent polarization value (2Pr) of SBT thin film with annealed at $780^{\circ}C$was$7.247{\mu}C/cm^2$and$8.485 {\mu}C/cm^2$by applying 3 V and 5 V, respectively.

• Journal of the Korean Ceramic Society
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• v.35 no.5
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• pp.472-478
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• 1998

Ferroelectric SrBi2Ta2O9(SBT) films were deposited on Pt/Ti/SiO2/Si substrates at 50$0^{\circ}C$ using a sintered SBT target Bi and Ta targets by modified rf magnetron sputtering and then were annealed at 80$0^{\circ}C$ for 10min in oxygen ambinet(760 torr) The composition of the SBT films could be easily controlled using the mul-ti-targets. The film composition of {{{{ {Sr }_{0.8 } {Bi }_{2.9 } {Ta}_{2.0 } {O }_{9 } }} was obtained with SBTd sputtering power of 100 W Bi of 25W and Ta of 10 W. A 250nm thick SBT films exhibited a dense and uniform microstructure and showed the remanent polarization(Pr) of 14.4 $\mu$C/cm2 and the coercive field({{{{ {E }_{c } }})of 60 kV/cm at applied voltage of 5 V. The SBT films show practically no polarization fatigue up to {{{{ {10 }_{10 } }} cycles under 5V bipolar pulse. The retention characteristics of the SBT films looked very promising and the leakage current density of the SBT films was about 1.23$\times${{{{ {10 }^{-7 } }}A/c{{{{ {m }^{2 } }} at 120kV/cm.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.96-97
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• 2002

불순물을 이용한 비휘발성 홀로그램저장[1,2]은 기존의 열정착을 광정착으로 대치하는 방법으로서 여러 가지 희토류 혹은 전이금속이온을 첨가한 LiMbO$_3$ (LNO) 단결정 재료에서 시도되고 있다. 대표적인 재료로서 Mn,Fe：LNO 가 있으나 Mn,Ce：LNO, Cu,Co：LNO, Tb,Fe：LNO 등도 연구되고 있고 Stoichiometric LNO 경우엔 Pr：LNO, Er：LNO, Tb：LNO 등이 연구되고 있다. 그 외에 Mn：YAlO$_3$도 약하긴 하지만 비휘발성이 최근 보고되었다. (중략)

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.2
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• pp.131-136
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• 2005

Beauveria bassiana F-101, which has high toxicity toward Acantholyda parki as well as Thecodiplosis japonensis, was an isolate to develop an alternative control system against the major forest pests. Up to now, in B. bassiana, only one pr1 gene has been isolated and characterized. Therefore, we here reported the identification of a pr1-like gene, which would be a factor of toxicity from B. bassiana F-101. The oligonucleotides for the amplification of the pr1-like gene, were chosen based on the conserved regions of the subtilisin family enzymes, pr1 genes of B. bassiana and Metarhizium anisopliae, and proteinase K of Tritirachium album. The cloned PCR fragment had 1111 bp including 52 bp intron. The deduced Pr1-like peptide showed a low identity with Pr1s of entomopathogenic fungi such as B. bassiana Pr1 (BbPr1) and M. anisopliae Pr1 (MaPr1) as well as the proteinase K of T. album (TaPrK). Instead, the deduced peptide had a substantially high amino acid sequence identity $(>65\%)$ with the serine proteases of Magnaporthe grisea (MgSPM1) and Podospora anserina (PaPspA). These results, therefore, appear to suggest that the putative Pr1-like peptide of B. bassiana F-101 belongs to the subtilisin-like serine protease family and may be a novel gene.