• Transactions on Electrical and Electronic Materials
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• v.9 no.1
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• pp.28-32
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• 2008

Hydrogenated microcrystalline silicon(${\mu}c$-Si:H) films were prepared using inductively coupled plasma chemical vapor deposition(ICP-CVD) method, electrical and optical properties of these films were studied as a function of silane concentration. And then, effect of $PH_3\;and\;B_2H_6$ addition on their electrical properties was also investigated for solar cell application. Characterization of these films from X-ray diffraction revealed that the conductive film exists in microcrystalline phase embedded in an amorphous network. At $PH_3/SiH_4$ gas ratio of $0.9{\times}10^{-3}$, dark conductivity has a maximum value of ${\sim}18.5S/cm$ and optical bandgap also a maximum value of ${\sim}2.39eV$. Boron-doped ${\mu}c$-Si:H films, satisfied with p-layer of solar cell, could be obtained at ${\sim}10^{-2}\;of\;B_2H_6/SiH_4$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.2
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• pp.143-150
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• 2000

Ferroelectric SrxBi2+yTa2O9+$\alpha$ thin films with various compositions(x=0.7, 0.8, 1, y=0.3, 0.4) were prepared by sol-gel method. The film with moled ratio of 0.8:2.3:2.0 in Sr/Bi/Ta, which was deposited on Pt/SiO2/Si (100), showed better ferroelectric properties than other films. To investigate substrate effects, the same compositions were spin coated on Pt/Ti/SiO2/Si (100) substrates. At an applied voltage of 5V, the dielectric constant($\varepsilon$r), remanent polarization (2Pr) and coercive field (Ec) of the Sr0.8Bi2.3Ta2O9+$\alpha$ thin film prepared on Pt/Ti/SiO2/Si (100) were about 296, 24$\mu$C/$\textrm{cm}^2$ and Ec of 49kV/cm respectively. Both SBT films firred at 80$0^{\circ}C$ revealed no fatigue up to 1010 cycles. Retention characteristics of these capacitors showed no degradation up to 104 sec.

• Journal of the Semiconductor & Display Technology
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• v.8 no.3
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• pp.13-17
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• 2009

we have studied characterization of microbolometer based on the co-sputtered silicon-antimony ($Si_{1-x}Sb_x$) thin film for infrared microbolometer. We have investigated the resistivity and the temperature coefficient of resistance (TCR) with annealing. We deposited the films using co-sputtering method at $200^{\circ}C$ in the Ar environment. The Sb concentration has been adjusted by applying variable DC power from Sb targets. TCR of deposited $Si_{1-x}Sb_x$ films have been measured the range of -2.3~-2.8%/K. The resistivity of the film is low but TCR is higher than the other bolometer materials. Resistivity of the films has not been affected hugely according to the low annealing temperature however the resistivity has been dramatically decreased over $250^{\circ}C$. It is caused of a phase change due to the rearrangement of Si and Sb atoms during crystallization process of the films.

• Korean Journal of Materials Research
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• v.2 no.5
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• pp.353-359
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• 1992

Thermal oxidation and plasma enhanced chemical vapor deposition of tantalum oxide thin films on p-type (100) Si substrates were studied to examine the dielectric nature of T$a_2O_5$ as a Al/T$a_2O_5$/p-Si capacitor. Microstructure and dielectric properties of the capacitors were investigated by XRD, AES, high frequency C-V analyzer, I-V meter and TEM. XRD analysis showed that the structure of T$a_2O_5$ films were amorphous, but the films were crystallized to hexagonal $\delta$-T$a_2O_5$ by 65$0^{\circ}C$ thermal oxidation treatment. It was found that the stoichiometry of the films was more or less close to 2 : 5. Leakage current density and relative dielectric constant of thermal oxidation T$a_2O_5$ film at 60$0^{\circ}C$ was 5.0${ imes}10^{-6}$/A/c$m^2 and 31.5, respectively. In the case of PECVD T$a_2O_5$film deposited at 0.47W/c$m^2 they were 2.5${ imes}10^{-5}$/A/$ extrm{cm}^2$ and 24.0, respectively. The morphology of the films and interfaces were investigated by TEM.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.140-143
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• 2002

In this study, we prepared ZnO/glass and $ZnO/SiO_{2}/Si$ thin film by Facing Targets Sputtering (FTS) system for Film Bulk Acoustic Resonator (FBAR). When the ZnO thin film applied to piezoelectric thin film, it requires good c-axis preferred orientation. And c-axis orientation has a remarkable difference with preparation conditions. Therefore, c-axis orientation must be significantly evaluated according to changing deposition conditions. Moreover, in order to prepare ZnO thin film with good crystallographic properties and progressive of efficiency of product process, the ZnO thin film should have to prepared as low temperature as possible. In this work, we prepared ZnO thin films on slide glass and $SiO_{2}/Si$ substrate. And the crystallographic characteristics of ZnO thin films on sputtering conditions were investigated by alpha-step and X-ray diffraction.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.8
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• pp.711-715
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• 2003

In this study, we prepared ZnO/glass and ZnO/SiO$_2$/Si thin film by Facing Targets Sputtering (FTS) system for Film Bulk Acoustic Resonator (FBAR). When the ZnO thin film applied to piezoelectric thin film, it requires good c-axis preferred orientation. And c-axis orientation has a remarkable difference with preparation conditions. Therefore, c-axis orientation must be significantly evaluated as a function of deposition conditions. Moreover, in order to prepare ZnO thin film with good crystallographic properties and progressive of efficiency of product process, the ZnO thin film should be prepared as low temperature as possible. In this work, we prepared ZnO thin films on slide glass and SiO$_2$/Si substrate. And the crystallographic characteristics of ZnO thin films on sputtering conditions were investigated by alpha-step and X-ray diffraction.

• Journal of the Korean Ceramic Society
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• v.31 no.11
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• pp.1330-1336
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• 1994

Ta2O5 films were deposited on the p-Si(100) substrates by ECR-PECVD and annealed in O2 atmosphere. The thicknesses of Ta2O5/SiO2 layers were measured by an ellipsometer and a cross-sectional TEM. Annealing in O2 atmosphere enhanced the stoichiometry of the Ta2O5 film and reduced the impurity carbon content. Ta2O5 films were crystallized at the annealing temperatures above 75$0^{\circ}C$. The best leakage current characteristics and the maximum dielectric constant of Ta2O5/SiO2 film capacitor were observed in the specimen annealed at $700^{\circ}C$ and 75$0^{\circ}C$, respectively. The flat band voltage of the Al/Ta2O5/SiO2/p-Si MOS capacitor was varied in the range of -0.6~-1.6 V with the annealing temperature. The conduction mechanism in the Ta2O5 film, the variation of the effective oxide charge density with the annealing temperature, and the effective electric field distribution in the Ta2O5/SiO2 double layer were also discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.2
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• pp.106-110
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• 1998

The $LiNbO_3$ thin films were prepared directly on Si(100) substrates by conventional RF magnetron spurttering system for nonvolatile memory applications. RTA(Rapid Thermal Annealing) treatment was performed for as-deposited films in an oxygen atmosphere at 600 $^{\circ}C$ for 60 s. The rapid thermal annealed films were changed to poly-crystalline ferroelectric nature from amorphous of as-deposition. The resistivity of the ferroelectric $LiNbO_3$ film was increased from a typical value of $1{\sim}2{\times}10^8{\Omega}{\cdot}cm$ before the annealing to about $1{\times}10^{13}{\Omega}{\cdot}cm$ at 500 kV/cm and reduced the interface state density of the $LiNbO_3/Si$ (100) interface to about $1{\times}10^{11}/cm^2{\cdot}eV$. Ferroelectric hysteresis measurements using a Sawyer-Tower circuit yielded remanent polarization ($P_r$) and coercive field ($E_c$) values of about 1.2 ${\mu}C/cm^2$ and 120 kV/cm, respectively.

• Electrical & Electronic Materials
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• v.11 no.11
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• pp.22-27
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• 1998

We have investigated the effect of an ion shower doping of the laser annealed poly-Si films at an elevated substrate temperatures. The substrate temperature was varied from room temperature to 300$^{\circ}C$ when the poly-Si film was doped with phosphorus by a non-mass-separated ion shower. Optical, structural, and electrical characterizations have been performed in order to study the effect of the ion showering doping. The sheet resistance of the doped poly-Si films was decreased from7${\times}$106 $\Omega$/$\square$ to 700 $\Omega$/$\square$ when the substrate temperature was increased from room temperature to 300$^{\circ}C$. This low sheet resistance is due to the fact that the doped film doesn't become amorphous but remains in the polycrystalline phase. The mildly elevated substrate temperature appears to reduce ion damages incurred in poly-Si films during ion-shower doping. Using the ion-shower doping at 250$^{\circ}C$, the field effect mobility of 120 $\textrm{cm}^2$/(v$.$s) has been obtained for the n-channel poly-Si TFTs.

• Korean Journal of Materials Research
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• v.4 no.1
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• pp.107-112
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• 1994

The phase transition and the surface and interface morphologies of $TiSi_2$ formed on atomically clean Si substrates are investigated. 200$\AA$ Ti and 400$\AA$ Si films on Si(ll1) have been codeposited at elevated temperatures (400~$800^{\circ}C$) in ultrahigh vacuum. The phase transition of TiSiL is characterized with using XRD. The results distinguish the formation of the C49 and C54 crystalline titanium silicides. The surface and interface morphologies of titanium silicides have been examined with SEM and TEM. A relatively smootb surface is observed for the C49 phase while a rough surface and interface are observed for C54 phase. The islanding of the C54 phase becomes severe at high temperature ($800^{\circ}C$). Islands of TiSiL have been observed at temperatures above $700^{\circ}C$ but no islands are observed at temperatures below $600^{\circ}C$. For films deposited at $400^{\circ}C$ and 500%. weak XRD peaks corresponding to TiSi were observed and TEM micrographs exhibited small crystalline regions of titanium silicide at the interface.