• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1573-1578
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• 2009

A computational study of the reactions between Zn-containing species, the products of the thermal decomposition of diethylzinc (DEZn) and water was investigated. The Zn-containing species – $C_2H_5)_2,\;HZnC_2H_5,\;and\;(ZnC_2H_5)_2$ – were assumed to react with water during ZnO metal organic chemical vapor deposition (MOCVD). Density functional theory (DFT) calculations at the level of B3LYP/6-311G(d) were employed for the geometry optimization and thermodynamic property evaluation. As a result dihydroxozinc, $Zn(OH)_2$, was the most probable reaction product common for all three Zn-containing species. A further clustering of $Zn(OH)_2$ was investigated to understand the initial stage of ZnO film deposition. In experiments, the reactions of DEZn and water were examined by in-situ Raman scattering in a specially designed MOCVD reactor. Although direct evidence of $Zn(OH)_2$ was not observed, some relevant reaction intermediates were successfully detected to support the validity of the gas phase reaction pathways proposed in the computational study.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.198-202
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• 2002

$HfO_2$films were grown on Si substrate in the temperature range $250~550^{\circ}C$ using metal organic chemical vapor deposition (MOCVD) technique for a gate dielectric. Hafnium tart-butoxide and Oxygen gas were used as precursors and N2 was used as carrier gas. Impurity distribution and film structure(including interfacial layer) were studied at the deposition temperature range between 25$0^{\circ}C$ and $550^{\circ}C$. The growth rate and impurty distribution decreased with increasing temperature. The electrical properties of $HfO_2$were investigated with C-V, 1-V method and showed it has a good properties as a gate dielectric.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.803-808
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• 1996

Material and electrical characteristies of copper thin films prepared by metal organic chemical vapor deposition (MOCVD) have been investigated for interconnection applications in ultra large scale integration circuits (ULSI). The copper films have been deposited a TiN substrates using a metal organic precursor, hexafluoro acetylacetonate trimethyvinylsilane copper, VTMS(hfac)Cu (I). Deposition rate, grain size, surface morphology, and electrical resistvity of the copper films have been measuredfrom samples prepared at various experimental conditions, which include substrate temperature, chamber pressure, and carrier gas flow rate. Results of the experiment showed that the electrical property of the copper films is closely related to the crystallinity of the films. Lowest electrical resistivity, $2.4{\mu}{\Omega}.cm$ was obtained at the substrate temperature of $180^{\circ}C$, but the resistivity slightly increased with increasing substrate temperature due to the carbon content along the copper grain boundaries.

• Bulletin of the Korean Chemical Society
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• v.23 no.2
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• pp.225-228
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• 2002

Amorphous $Ga_2O_3$ films have been grown on Si(100) substrates by metal organic chemical vapor deposition (MOCVD) using gallium isopropoxide, $Ga(O^iPr)_3$, as single precursor. Deposition was carried out in the substrate temperature range 400-800 $^{\circ}C$. X-ray photoelectron spectroscopy (XPS) analysis revealed deposition of stoichiometric $Ga_2O_3$ thin films at 500-600 $^{\circ}C$. XPS depth profiling by $Ar^+$ ion sputtering indicated that carbon contamination exists mostly in the surface region with less than 3.5% content in the film. Microscopic images of the films by scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed formation of grains of approximately 20-40 nm in size on the film surfaces. The root-mean-square surface roughness from an AFM image was ${\sim}10{\AA}$. The interfacial layer of the $Ga_2O_3$/Si was measured to be ${\sim}35{\AA}$ thick by cross-sectional transmission electron microscopy (TEM). From the analysis of gaseous products of the CVD reaction by gas chromatography-mass spectrometry (GC-MS), an effort was made to explain the CVD mechanism.

• Journal of the Korean Vacuum Society
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• v.11 no.4
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• pp.194-200
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• 2002

MOCVD(metal-organic chemical vapor deposition) copper thin film was annealed at various conditions and the eletrical properties and micro-structures were investigated to find the optimal annealing condition and its effect. Cu thin film annealed at Ar 1 torr, $400^{\circ}C$ had the most improved resistivity of 1.98 $\mu\Omega$cm, and texture; the ratio of $I_{(111)}/I_{(200)}$ was varied from 2.03 to 3.11, and Cu thin film annealed at Ar 1 torr, $450^{\circ}C$ had the largest grain size and uniformity. After the annealing, the EM(electromigration) test was followed to ensure the improved properties by annealing. Compare to other conditions, Cu patterns annealed at Ar 1 torr, $400 ^{\circ}C$ had the most improved properties when it came to the EM resistance, which was due to the low resistivity, the preferential evolution of texture to (111) plane, and the reduction of surface roughness of annealed copper film.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.2 s.31
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• pp.29-35
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• 2004

Hafnium-oxide gate dielectric films deposited by a metal organic chemical vapor deposition technique on a $N_2-plasma$ treated SiNx and a hydrogen-terminated Si substrate have been investigated. In the case of $HfO_2$ film deposited on a hydrogen-terminated Si substrate, suppressed crystallization with effective carbon impurity reduction was obtained at $450^{\circ}C$. X-ray photoelectron spectroscopy indicated that the interface layer was Hf-silicate rather than phase separated Hf-silicide and silicon oxide structure. Capacitance-voltage measurements show equivalent oxide thickness of about 2.6nm for a 5.0 nm $HfO_2/Si$ single layer capacitor and of about 2.7 nm for a 5.7 nm $HfO_2/SiNx/Si$ stack capacitor. TEM shows that the interface of the stack capacitor is stable up to $900^{\circ}C$ for 30 sec.

• Korean Journal of Materials Research
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• v.11 no.5
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• pp.361-366
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• 2001

It is difficult to obtain high Cu nucleation density and continuous Cu films in Cu-MOCVD without cleaning the TiN substrate prior to Cu deposition. In this study effects of plasma precleaning on the Cu nucleation density were investigated using SEM, XPS, AES, AFM analyses. Direct plasma pretreatment is much more effective than remote plasma pretreatment in enhancing Cu nucleation. Cleaning effects are enhanced with increasing the rf-power and the plasma exposure time in hydrogen plasma pretreatment. The mechanism through which Cu nucleation is enhanced by plasma pretreatment is as follows: Hydrogen ion\ulcorner in the hydrogen plasma react with TiN to form Ti and $NH_3$ Cu nucleation is easier on the Ti substrate than TiN substrate.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.377-377
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• 2012

Microprocessor technology now relies on copper for most of its electrical interconnections. Because of the high diffusivity of copper, Atomic layer deposition (ALD) $TaN_x$ is used as a diffusion barrier to prevent copper diffusion into the Si or $SiO_2$. Another problem with copper is that it has weak adhesion to most materials. Strong adhesion to copper is an essential characteristic for the new barrier layer because copper films prepared by electroplating peel off easily in the damascene process. Thus adhesion-enhancing layer of cobalt is placed between the $TaN_x$ and the copper. Because, cobalt has strong adhesion to the copper layer and possible seedless electro-plating of copper. Until now, metal film has generally been deposited by physical vapor deposition. However, one draw-back of this method is poor step coverage in applications of ultralarge-scale integration metallization technology. Metal organic chemical vapor deposition (MOCVD) is a good approach to address this problem. In addition, the MOCVD method has several advantages, such as conformal coverage, uniform deposition over large substrate areas and less substrate damage. For this reasons, cobalt films have been studied using MOCVD and various metal-organic precursors. In this study, we used $C_{12}H_{10}O_6(Co)_2$ (dicobalt hexacarbonyl tert-butylacetylene, CCTBA) as a cobalt precursor because of its high vapor pressure and volatility, a liquid state and its excellent thermal stability under normal conditions. Furthermore, the cobalt film was also deposited at various $H_2/NH_3$ gas ratio(1, 1:1,2,6,8) producing pure cobalt thin films with excellent conformality. Compared to MOCVD cobalt using $H_2$ gas as a reactant, the cobalt thin film deposited by MOCVD using $H_2$ with $NH_3$ showed a low roughness, a low resistivity, and a low carbon impurity. It was found that Co/$TaN_x$ film can achieve a low resistivity of $90{\mu}{\Omega}-cm$, a low root-mean-square roughness of 0.97 nm at a growth temperature of $150^{\circ}C$ and a low carbon impurity of 4~6% carbon concentration.

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.05a
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• pp.108-108
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• 2001

• 한국초전도학회:학술대회논문집
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• v.14
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• pp.72-72
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• 2004