• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.9
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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.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.2
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• pp.87-90
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• 2008

Co-Pt alloy thin films were galvanostatically electrodeposited on Ru (30 nm)/Ta (5 nm)/Si (100) substrates from a amino-citrate based electrolyte. We used Ru(0002)-oriented buffer layers to control the crystallinity and orientation of the Co-Pt alloy thin films. The effect of solution temperature on the microstructure and magnetic properties of the Co-Pt alloy thin film was investigated. The samples were characterized by EDS, FESEM, XRD diffractometer using Cu $K{\alpha}$ radiation. The magnetic properties of these films were analyzed by a VSM and torque magnetometer. The Co-Pt alloy thin films were exhibited very high out-of-plane coercivity and squareness of the multilayer were 6527 Oe and 0.93, respectively, without heat treatment.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.167-167
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• 2011

Magnetic random access memory (MRAM) is one of the prospective semiconductor memories for next generation. It has the excellent features including nonvolatility, fast access time, unlimited read/write endurance, low operating voltage, and high storage density. MRAM consists of magnetic tunnel junction (MTJ) stack and complementary metal-oxide semiconductor (CMOS). The MTJ stack is composed of various magnetic materials, metals, and a tunneling barrier layer. For the successful realization of high density MRAM, the etching process of magnetic materials should be developed. Among various magnetic materials, FePt has been used for pinned layer of MTJ stack. The previous etch study of FePt magnetic thin films was carried out using $CH_4/O_2/NH_3$. It reported only the etch characteristics with respect to the variation of RF bias powers. In this study, the etch characteristics of FePt thin films have been investigated using an inductively coupled plasma reactive ion etcher in various etch chemistries containing $CH_4$/Ar and $CH_4/O_2/Ar$ gas mixes. TiN thin film was employed as a hard mask. FePt thin films are etched by varying the gas concentration. The etch characteristics have been investigated in terms of etch rate, etch selectivity and etch profile. Furthermore, x-ray photoelectron spectroscopy is applied to elucidate the etch mechanism of FePt thin films in $CH_4$/Ar and $CH_4/O_2/Ar$ chemistries.

• Journal of the Korean Magnetics Society
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• v.6 no.2
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• pp.93-97
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• 1996

The effects of annealing after deposition on the magnetic and magneto-optical properties of MnSbPt thin films prepared by rf sputtering were investigated. The MnSbPt alloy thin films were annealed in a vacuum with $10^{-5}$ Torr and the air, respectively, as a function of temperature and time. The films annealed at $300^{\circ}C$ for 4 hours was found to have the highest value of the saturation magnetization. The films annealed in the air did not show any thermal degradations, which indicates their chemical stability for the magneto-optical recording process. It was revealed that the $Mn_{43}Sb_{46}Pt_{11}$ films annealed at $300^{\circ}C$ for 4hours in a vacuum with $10^{-5}$ Torr exhibit high Kerr rotation angle of $0.8^{\circ}$ for the incident wavelength of 550nm, which is ascribed to the increase of the volume ratio of Clb phase. However, similar to the PtMnSb alloy thin films, these films are still horizontally magnetized and have the coercive field less than 400 Oe.

• Journal of Sensor Science and Technology
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• v.16 no.2
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• pp.159-164
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• 2007

Thin films of platinum were deposited on a $Al_{2}O_{3}/ONO(SiO_{2}-Si_{3}N_{4}-SiO_{2})/Si$-substrate with an 2-inch Pt(99.99 %) target at room temperature for 20, 30 and 60 min by DC magnetron sputtering, respectively X-ray diffract meter (XRD) was used to analyze the crystallanity of the thin films and field emission scanning electron microscopy (FE-SEM) was employed for the investigation on crystal growth. The densification and the grain growth of the sputtered films have a considerable effect on sputtering time and annealing temperatures. The resistance of the Pt thin films was decreased with increasing deposition time and sintering temperature. Pt micro heater thin film deposited for 60 min by DC magnetron sputtering on an $Al_{2}O_{3}$/ONO-Si substrate and annealed at $600^{\circ}C$ for 1 h in air is found to be a most suitable micro heater with a generation capacity of $350^{\circ}C$ temperature and 645 mW power at 5.0 V input voltage. Adherence of Pt thin film and $Al_{2}O_{3}$ substrate was also found excellent. This characteristic is in good agreement with the uniform densification and good crystallanity of the Pt film. Efforts are on progress to find the parameters further reduce the power consumption and the results will be presented as soon as possible.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1250_1251
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• 2009

The SBN thin films are deposited on Pt-coated electrode(Pt/Ti/$SiO_2$/Si) using RF sputtering method at various deposition conditions. The capacitance of SBN thin films were increased with the increase of Ar/$O_2$ ratio and RF power, respectively. Also, The capacitance of SBN thin films were increased with the increase of deposition temperature.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.1
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• pp.53-59
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• 2003

Using Platinum-silicide (PtSi) formed between silicon substrate and carbon film, we have improved the field emission of electrons from carbon films. Pt films were deposited on n-Si(100) substrates at room temperature by DC sputter technique. After deposition, these PtSi thin films were annealed at 400 ~ $600^{\circ}C$ in a vacuum chamber, and the carbon films were deposited on those Pt/Si substrates by laser ablation at room temperature. The field emission property of C/Pt/Si system is found to be better than that of C/Si system and it is showed that property was improved with increasing annealing temperature. The reasons why the field emission from carbon film was improved can be considered as follows, (1)the resistance of carbon films was decreased due to graphitization, (2)electric field concentration effectively occurred because the surface morphology of carbon film deposited on Pt/si substrates with rough surface, (3)it is showed that annealing induced reaction between Pt film and Si substrate, as a consequence that the interfacial resistance between Pt film and Si substrate was decreased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.150-153
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• 1999

The electrical and physical characteristics of MgO and Pt thin-films on Si wafers deposited by r.f magnetron sputtering, were analyzed with annealing condition(100$0^{\circ}C$, 120 min) by four point probe, SEM and XRD. Until annealing temperature of 100$0^{\circ}C$, MgO had the properties of improving Pt adhesion to SiO$_2$ and insulation without chemical reaction to Pt thin-films and the resistivity of Pt thin-films was improved. The thermal characteristics of Pt micro-heater were analyed with Pt-RTD integrated on the same substrate, In the analysis of properties of Pt-RTD, TCR value had 3927 ppm/$^{\circ}C$ and liner in the temperature range of 25~40$0^{\circ}C$ temperature of Pt micro-heater had up to 40$0^{\circ}C$ with 1.5 watts of the heating power.

• Korean Journal of Crystallography
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• v.11 no.2
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• pp.95-101
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• 2000

Ferroelectric SrBi2Ta2O9 (SBT) thin films of Pt/Ti/SiO2 electrode were fabricated using a sintered SBT target with various Bi2O3 content by rf magnetron sputtering. Good hysteresis loop characteristics were observed in the SBT thin films deposited with 50mol% excess Bi target. SBT thin films crystallized from 650℃ however, good hysteresis loop can be obtained in the film annealed above 700℃. pt/TiO2/SiO2 and Pt/SiO2 electrodes were also used to investigate the Pt electrode dependence of SBT thin films. SBT thin films showed random oriented polycrystalline structure and similar morphology regardless of electrodes with quite different surface morphology. A 0.2㎛ thick SBT film annealed at 750℃ exhibited the remanent polarization (2Pr) of μC/㎠ and coercive voltage(Vc) of 1V at an applied voltage of 5V.

• Journal of the Korean Ceramic Society
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• v.36 no.4
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• pp.403-409
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• 1999

The dielectric and pyroelectric properties of $Ba_{0.66}$$Sr_{0.38}$$TiO_{3}$(BST) thin films growtn on Pt/Ti/NON/Si us-ing RF magnetron sputtering have been investigated. With increasing the substrate temperature during de-position of the BST film in the range of 300-$600^{\circ}C$ the dielectric and pyroelectric constants of the film were increased due to improved crystallinity of the film. In addition the dependence of the microstructural and electrical properties of BST films onthe deposition temperature of the bottom Pt electrode was studied. The preferred orientation of the BST films as well as the microstructure of the Pt film was greatly in-fluenced by the deposition temperature of the bottom Pt electrode was studied. The preferred orientation of the BSt films as well as the microstructure of the Pt film was greatly in-fluenced by the deposition temperature of the bottom Pt electrodes. and thus so were the pyrolelectric pro-perties of the BST film. The highest value of pyroelectric coefficient at room temperature obtained in this work was $nCcm^{-2}K^{-1}$ which is much higher than those previously reported on other perovskite fer-roelectric thin films.