• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.93-96
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• 2002

In this study, PZT thin films were fabricated using sol-gel processing onto Si/$SiO_2$/Ti/Pt substrates. PZT sol with different Zr/Ti ratio(20/80, 30/70, 40/60, 52/48) were prepared, respectively. The films were fabricated by using the spin-coating method on substrates. The films were heat treated at $450^{\circ}C$, $650^{\circ}C$ by rapid thermal annealing(RTA). The preferred orientation of the PZT thin films were observed by X-ray diffraction(XRD), and Scanning electron microscopy(SEM). All of the resulting PZT thin films were crystallized with perovskite phase. The fine crystallinity of the films were fabricated. Also, we found that the ferroelectric properties from the dielectric constant of the PZT thin films were over 600 degrees, P-E hysteresis constant. And the leakage current densities of films were lower than $10^{-8}A/cm^2$. It is concluded that the PZT thin films by sol-gel process to be convinced of application for ferroelectric memory device.

• Journal of the Korean Vacuum Society
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• v.4 no.S1
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• pp.145-150
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• 1995

PZT thin films were fabricated on Pt/Ti/SiO2/Si substrates at $500^{\circ}C$ by ECR-PECVD for the application to the charge storage capacitor of ULSI DRAMs. Perovskite single phase PZT films were obtained by controling the film compositional ratio Pb/(Zr+Ti) close to 1. The anion concentrations in the PZT films were successfully controlled by adjusting the flow rates of each MO sources. Capacitance of a typical 94 nm thick PZT film prepared at $500^{\circ}C$ in this work was about 5.3 uF/$\textrm{cm}^2$, which corresponds to the equivalent SiO2 thickness of 0.65nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.287-290
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• 1998

It was investigated that the dielectric properties of ferroelectric materials using PZT-5A and PZT thin films. PZT-5A was 20mm diameters, 0.71mm, 0.51mm and 0.41mm thickness respectively and having c-axis preferred orientation. Electrodes(Al) were deposited by evaporation method. PZT thin film was deposited on Pt/SiO$_2$/Si substrate by RF magnetron sputtering method, and annealed at 750$^{\circ}C$ with RTA. Dielectric constants were measured automatically by computer measuring system. Dielectric constants were changed rapidly from 817 to 888 in 0.41mm thickness PZT-5A, 823 to 890 in 0.51mm and 822 to 839 in 0.71mm as the electric field grown. In the case of PZT thin film, dielectric constants were changed from 724 to 1173 in 4500${\AA}$ thickness, 721 to 1204 in 5500${\AA}$ thickness and 811 to 1407 in 7000${\AA}$ thickness.

• Journal of Integrative Natural Science
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• v.8 no.4
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• pp.244-249
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• 2015

The PZT thin films were deposited on Si(100) substrate using RF magnetron sputtering method. And the PZT thin films were post annealed at various temperatures to form perovskite phase. To analyze PZT thin films, surface profiler, XRD, XPS, CA, and SFE were used. The thickness increased from 536.5 to 833.2 nm as post annealing temperature increased. The perovskite PZT was observed from PZT-823 and pyrochlore PZT, $ZrO_2$, $TiO_2$, and perovskite $PbZrO_3$ were observed. From the XPS, the atomic percentages of Pb, Zr, Ti, and O were calculated and the portion of Pb increased to PZT-823 and decreased to PZT-923 and then increased to PZT-1023. Also, the CA and SFE was effected on post annealing temperature and as a function of atomic percentage of Pb, the CA and SFE was transformed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.641-643
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• 2003

The ferroelectric properties of PZT(53/47) thin film was investigated by methoxy enthanol solution based on sol-gel method. The thickness of each layer by spincoating 0.25M sol at one time was $0.1{\mu}m$ and crack-free film was formed. $LaNiO_3/Si(100)$ electrode and $Pt/Ti/SiO_2/Si(100)$ electrode was coated by PZT sol at several times. PZT orientation was confirmed as a method of XRD and coercive field(Ec) as well as remnant polarization(Pr) was investigated from hysterisis curve. As a result of XRD analysis, we can know that the orientation of on PZT/LNO/Si(100) is better than on $Pt/Ti/SiO_2/Si(100)$. The remnant polarization(Pr) in LNO electrode was $87.5{\mu}C/cm^2$ and $39.8{\mu}C/cm^2$ in Pt. From this figures, it is investigated that the Pr in LNO electrode was better than in Pt.

• Journal of Sensor Science and Technology
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• v.19 no.3
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• pp.202-208
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• 2010

This study examined the dependency of crystalline orientation and electric properties of sol-gel PZT film on hydrolysis, a $PbTiO_3$ seed layer and a concentration of sol-gel solution. The PZT thin films were prepared by using 2-Methoxyethanol-based sol-gel method and spin-coating on Pt/Ti/$SiO_2$/Si substrates. The 1-${\mu}m$-thick PZT films were coated and then fired in a furnace by direct insert method. The highly (111) oriented PZT film of pure perovskite structure could be obtained. We could control the degree of orientation by various parameters such as hydrolysis, a $PbTiO_3$ seed layer and a concentration of sol-gel solution. The highest measured remanent polarization, dielectric constant and piezoelectric coefficient are $24.16\;{\mu}C/cm^2$, 2808, and 159 pC/N, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.3
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• pp.406-414
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• 1996

We studied the phase formation and the effect of electrical properties of PZT thin films with changing the oxygen partial pressure in cooling after deposition of PZT thin film by reactive sputtering method. The roughness of thin film increased with decreasing the oxygen partial pressure in cooling due to the evaporation on the surface ofthin films and the grain size was not changed very much. The hysteresis property of PZT thin film was improved toward having a good squareness with increasing the cooling oxygen partial pressure. We observed the decrease of remanent polarization, retained polarization and coercive field with decreasing the oxygen partial pressure. Dielectric constant decreased gradually and internal bias field increased in the measurement of dielectric constant-voltage property with decreasing cooling oxygen partial pressure. We observed the increase of nonswitched polarization in the measurement of field accelerated retention and the decrease of nonswitched polarization with increasing the bias time.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.801-803
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• 1998

We investigated Pt and $RuO_2$ as a bottom electrode and PZT thin film for ferroelectric applications. XRD examination shows that a mixed phase of (111) and (200) Pt peak for the temperature ranged from RT to $200^{\circ}C$, and a preferred (111) orientation for the substrate temperature of $300^{\circ}C$. From the XRD and AFM results, we recommend the substrate temperature of $300^{\circ}C$, 80 W for the Pt bottom electrode growth. From the study of an oxygen partial pressure from 0 to 50%, we learned that only Ru metal was grown with $0{\sim}5%$, a mixed phase of Ru and $RuO_2$ for $10{\sim}40%$, pure $RuO_2$ at 50%. Having optimized the bottom electrode growth conditions, we employed two step process in PZT film capacitor: PZT film growth at the low substrate temperature of $300^{\circ}C$ and then post RTA anneal treatments. PZT films were randomly oriented on $RuO_2$ and (110) preferentially oriented on Pt electrode. Leakage current density of PZT film demonstrated two to three orders higher for $RuO_2$ bottom electrode. From C-V results we observed a dielectric constant of PZT film higher than 1200. This paper presents the optimized process conditions of the bottom electrodes and properties of PZT thin films on these electrodes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.394-397
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• 2001

In this paper, in-situ deposited $Ru/RuO_2$ bottom electrodes have been investigated as new bottom electrodes for PZT thin film capacitor application. As a comparison, structural and electrical properties of PZT thin films on Pt/Ti and $RuO_2$ bottom electrodes are also investigated. The use of $Ru/RuO_2$ hybrid electrodes showed better electrical properties in compression with $RuO_2$ bottom electrode. With increasing Ru electrode thickness, the PZT thin films showed preferred orientation along the (110) direction and and leakage current of PZT thin films were improved. The PZT thin films on Ru (100nm)/$RuO_2$ electrodes exhibited excellent ferroelectric properties such as remant polarization and coercive field of $7.2C/cm^2$ and 46.35 kV/cm, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.394-397
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• 2001

In this paper, in-situ deposited Ru/RuO$_2$ bottom electrodes have been investigated as new bottom electrodes for PZT thin film capacitor application. As a comparison, structural and electrical properties of PZT thin films on Pt/Ti and RuO$_2$ bottom electrodes are also investigated. The use of Ru/RuO$_2$ hybrid electrodes showed better electrical properties in compression with RuO$_2$ bottom electrode. With increasing Ru electrode thickness, the PZT thin films showed preferred orientation along the (110) direction and leakage current of PZT thin films were improved. The PZT thin films on Ru (100nm)/RuO$_2$ electrodes exhibited excellent ferroelectric properties such as remant polarization and coercive field of 7.2 C/$\textrm{cm}^2$ and 46.35 kV/cm, respectively.