• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.5
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• pp.247-252
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• 2002

$(Pb_{1-x}La_x)TiO_3$ (x = 0.1) thin films were prepared on ITO-coated glass substrates by metal organic chemical vapor deposition using ultrasonic spraying. Effects of the post-annealing and the seeding layer on crystallization, microstructures and electrical properties of thin films were investigated. Dielectric constants of films increased due to the modification of crystallization and the changing of a surface morphology by applying the post-annealing. In addition, as the application of PT seed- ing layer offered nucleation sites to PLT thin films, electrical properties of films were enhanced by the increase of crys-tallinity and grain size. The dielectric constant of the films post-heated for 60 min and with a seeding layer was 213 at 1 kHz.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.1
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• pp.34-46
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• 2004

Copper films were prepared by using ECR-MOCVD(Electron Cyclotron Resonance Metal Organic Chemical Vapor Deposition) coupled with a DC bias system. The DC bias is connected to the electrode which placed 1∼3cm above the polymer substrate. The pulse electrical field around the electrode attracts the positive charged copper ions generated from the dissociation of copper precursor, $Cu(hfac)_2$, under ECR plasma. Condensation of supersaturated copper ions in the space between the electrode and substrate, makes it possible to deposit copper film on the polymer substrate even at room temperature. In this study, optimization of the electrode configuration was carried out in order to obtain the uniform films. The uniformity of the deposited films were closely related to the parameters of electrode geometry such as electrode shape, thickness, grid size and the spacing between electrodes. The most uniform copper film was observed with the electrode that enabled uniform electrical field distribution across the whole dimension of electrode.

• Korean Journal of Materials Research
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• v.11 no.1
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• pp.20-26
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• 2001

The deposition characteristics of MOCVO Cu using the (hfac)Cu(I) (1,5-DMCOD)(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato Cu(I) 1,5-dimethyl-cyclooctadine) as a precursor have been investigated in terms of the effects of hydrogen and H(hfac) ligand addition with He carrier gas. MOCVD Cu using a Helium carrier gas showed a low deposition rate (20~$125{\AA}/min$) at the substrate temperature range of 180~$230^{\circ}C$. Moreover, the Cu film deposited at 19$0^{\circ}C$ was very thin (~$700{\AA}$) and showed the lowest resistivity value of $2.8{\mu}{\Omega}-cm$. The deposition rate of MOCVD Cu using $H_2$or H(hfac) addition was significantly enhanced especially at the low temperature region (180~$190^{\circ}C$). Furthermore, thinner Cu films (~$500{\AA}$) provided low resistivity (3.6~$2.86{\mu}{\Omega}-cm$). From surface reflectance measurement, very thin films deposited by using different gas system revealed good surface morphology comparable with sputtered Cu film ($300^{\circ}C$, vacuum-anneal). Hence, Cu film using (hfac)Cu(1,5-DMCOD) as a precursor is expected as a good seed layer in the electrochemical deposition process for Cu metallization.

• Progress in Superconductivity and Cryogenics
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• v.6 no.3
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• pp.16-20
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• 2004

YB $a_2$C $u_3$$O_{7-x}$ (YBCO) films were deposited on (100) SrTi $O_3$ single crystal substrates by a metal organic chemical vapor deposition (MOCVD) system of hot-wall type using single liquid source. Under the condition of the mole ratio of Y(tmhd)$_3$:Ba(tmhd)$_2$:Cu(tmhd)$_2$= 1:2.1:2.9. the deposition pressure of 10 Torr. the MO source line speed of 15 cm/min. the Ar/ $O_2$ flow rate of 800/800 sccm. YBCO films were prepared at the deposition temperatures of 780∼89$0^{\circ}C$. In case of the YBCO films with 2.2 ${\mu}{\textrm}{m}$ thickness deposited for 6 minutes at 86$0^{\circ}C$. XRD pattern showed complete c-axis growth and SEM morphology showed dense and crack-free surface. The atomic ratios of Ba/Y and Cu/Ba in the film were 1.92 and 1.56. respectively. The deposition rate of the film was as high as 0.37 ${\mu}{\textrm}{m}$/min. The critical temperature ( $T_{c.zero}$) of the film was 87K. The critical current of the film was 104 A/cm-width. and the critical current density was 0.47 MA/$\textrm{cm}^2$. For the thinner film of 1.3 ${\mu}{\textrm}{m}$ thickness. the critical current density of 0.62 MA/$\textrm{cm}^2$ was obtained.d.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.155-159
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• 2003

Polycrystalline $Ti_{1-x}Co_xO_2$ thin films on $SiO_2$ (200 nm)/Si (100) substrates were prepared using liquid-delivery metalorganic chemical vapor deposition. Microstructures and ferromagnetic properties were investigated as a function of doped Co concentration. Ferromagnetic behaviors of polycrystalline films were observed at room temperature, and the magnetic and structural properties strongly depended on the Co distribution, which varied widely with doped Co concentration. The annealed $Ti_{1-x}Co_xO_2$ thin films with $x{\leq}0.05$ showed a homogeneous structure without any clusters, and pure ferromagnetic properties of thin films are only attributed to the $Ti_{1-x}Co_xO_2$ (TCO) phases. On the other hand, in case of thin films above x=0.05, Co clusters formed in a homogeneous $Ti_{1-x}Co_xO_2$ Phase, and the overall ferromagnetic (FM) properties depended on both $FM_{TCO}$ and $FM_{Co}$. Co clusters with about 10nm-150nm size decreased the value of Mr (the remanent magnetization) and increased the saturation magnetic field.

• Korean Journal of Materials Research
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• v.5 no.7
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• pp.775-780
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• 1995

Thin films of titanium nitride are formed using the tetrakis-dimethyl-amino-titanium (TDMAT(Ti[N($CH_3$)$_2$]$_4$)) under various conditions. The formation of TiN films has been obtained from the thermal decomposition of the Ti-precursor and the gas phase reaction between TDMAT and ammonia(NH$_3$). The resistivity of the MOCVD film can be attributed to their impurity. Especially the curve fitting graph of XPS data is revealed that main impurities in the films as carbon and oxygen make various interstitial compounds which has influenced physical and electrical properties of the film. In the contact hole with the aspect ratio of 3:1 and the diameter of 0.5${\mu}{\textrm}{m}$, the SEM morphology shows that the step coverage is more decreased in the films formed y flowing ammonia additionally than the films formed by pyrolysis of TDMAT and the phenomenon is probably related with the activation energy.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.25.2-25.2
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• 2009

Vertically aligned zinc oxide(ZnO) nanorods (NRs) with different surface morphology were grown by metal organic chemical vapor deposition (MOCVD) on sapphire substrate with different deposition condition. Based on the surface morphology, ZnO nanostructures are divided into three types: nanoneedles, nanonails and nanorods with rounded tip. Variable temperature photoluminescence (PL) have employed to probe the exciton recombination in high density and vertically aligned ZnO Nanorod arrays. Low temperature photoluminescence measurements do not show any significant yellow emission, but the near band edge excitonic emission shows very strong dependence with the surface morphology. The recombination properties are expected to be different due to different surface-to-volume ratio and distribution of potential fluctuations of intrinsic defects.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.249-249
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• 2010

The effect of forming a passivation layer was investigated in superconformal Cu gap-filling of the nano-scale trench with atomic-layer deposited (ALD)-Ru glue layer. It was discovered that the nucleation and growth of Cu during metal-organic chemical vapor deposition (MOCVD) were affected by hydrogen plasma treatments. Specifically, as the plasma pretreatment time increased, Cu nucleation was suppressed proportionally. XPS and Thermal Desorption Spectroscopy indicated that hydrogen atoms passivate the Ru surface, which leads to suppression of Cu nucleation owing to prevention of adsorption of Cu precursor molecules. For gap-fill property, sub 60-nm ALD Ru trenches without the plasma pretreatment was blocked by overgrown Cu after the Cu deposition. With the plasma pretreatment, superconformal gap filling of the nano-scale trenches was achieved due to the suppression of Cu nucleation near the entrances of the trenches. Even the plasma pretreatment with bottom bias leads to the superconformal gap-filling.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.4
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• pp.149-153
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• 2021

ε-Ga₂O₃ thin films were grown on 4H-SiC substrates by metal organic chemical vapor deposition (MOCVD) and crystalline quality were evaluated depend on growth conditions. It was found that the best conditions of the ε-Ga₂O₃ were grown at a growth temperature of 665℃ and an oxygen flow rate of 200 sccm. Two-dimensional growth was completed after the merge of hexagonal nuclei, and the arrangement direction of hexagonal nuclei was closely related to the crystal direction of the substrate. However, it was confirmed that crystal structure of the ε-Ga₂O₃ had an orthorhombic rather than hexagonal. Crystal phase transformation was performed by thermal treatment. And a β-Ga₂O₃ thin film was grown directly on 4H-SiC for the comparison to the phase transformed β-Ga₂O₃ thin film. The phase transformed β-Ga₂O₃ film showed better crystal quality than directly grown one.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.319-319
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• 2013

Even though the fabrication methods of metal oxide based thin film capacitor have been well established such as RF sputtering, Sol-gel, metal organic chemical vapor deposition (MOCVD), ion beam assisted deposition (IBAD) and pulsed laser deposition (PLD), an applicable capacitor of printed circuit board (PCB) has not realized yet by these methods. Barium Strontium Titanate (BST) and other high-k ceramic oxides are important materials used in integrated passive devices, multi-chip modules (MCM), high-density interconnect, and chip-scale packaging. Thin film multi-layer technology is strongly demanded for having high capacitance (120 nF/$mm^2$). In this study, we suggest novel multi-layer thin film capacitor design and fabrication technology utilized by plasma assisted deposition and photolithography processes. Ba0.6Sr0.4TiO3 (BST) was used for the dielectric material since it has high dielectric constant and low dielectric loss. 5-layered BST and Pt thin films with multi-layer sandwich structures were formed on Pt/Ti/$SiO_2$/Si substrate by RF-magnetron sputtering and DC-sputtering. Pt electrodes and BST layers were patterned to reveal internal electrodes by photolithography. SiO2 passivation layer was deposited by plasma-enhanced chemical vapor deposition (PE-CVD). The passivation layer plays an important role to prevent short connection between the electrodes. It was patterned to create holes for the connection between internal electrodes and external electrodes by reactive-ion etching (RIE). External contact pads were formed by Pt electrodes. The microstructure and dielectric characteristics of the capacitors were investigated by scanning electron microscopy (SEM) and impedance analyzer, respectively. In conclusion, the 0402 sized thin film multi-layer capacitors have been demonstrated, which have capacitance of 10 nF. They are expected to be used for decoupling purpose and have been fabricated with high yield.