Chemical Vapor Deposition (CVD) of ZrC Coatings from ZrCl4-C3H6-H2

2011 ◽  
Vol 189-193 ◽  
pp. 648-652 ◽  
Author(s):  
Qiao Mu Liu ◽  
Li Tong Zhang ◽  
Zhi Xin Meng ◽  
Lai Fei Cheng

ZrC coatings were prepared by CVD using ZrCl4, C3H6, and H2as the precursors. The mechanisms responsible for the effects of deposition temperature, H2flow rate and inlet C/Zr ratio on the ZrC coatings were studied based on the deposition mechanism of ZrC. The results indicate that the ZrC morphologies change from a loose spherical structure to a cauliflower structure, then to a glassy structure as the deposition temperature increases from 1050°C to 1150°C, then to 1250°C. The carbon content in the ZrC coatings increases with increasing the deposition temperature. Higher inlet C/Zr ratio can lead to rough surfaces and higher carbon content. Reasonable H2concentration can inhibit carbon deposition, and lead to a cauliflower structure.

1999 ◽  
Vol 607 ◽  
Author(s):  
P.N.K. Deenapanray ◽  
H.H. Tan ◽  
C. Jagadish

AbstractWe have investigated the influence of SiOx capping layer quality on impurity-free vacancy interdiffusion in GaAs/Al0.54Ga0.46As quantum wells. Dielectric layers were deposited by plasmaenhanced chemical vapor deposition, and properties of layers were changed by varying either the flow rate of silane or deposition temperature. The extent of intermixing in our samples is discussed in terms of the 0 content and incorporation of N in capping layers, and also on their porosity. We also report on the electrically active defects which are introduced in Si02 capped and annealed n-GaAs, and relate them to the intermixing process.


1999 ◽  
Vol 606 ◽  
Author(s):  
J. Lubguban ◽  
Y. Kurata ◽  
T. Inokuma ◽  
S. Hasegawa

AbstractSiO2:F:C films were deposited using a plasma-enhanced chemical vapor deposition (PECVD) technique from SiH4/O2/CF4/CH4 mixtures. Increasing amount of carbon were introduced to the SiO2:F films by changing the CH4 flow rate, [CH4], while keeping constant other conditions such as rf power and deposition temperature, TD. It was found that the addition of CH4 decreases the dielectric constant, k; from 3.36 for [CH4] = 0 sccm to 2.95 for [CH4] = 8 sccm. For the [CH4] condition where the film has a lowest k, the deposition temperature and rf power were optimized by depositing films using different values of TD and rf power The k for films in the new series as well as the stress and water absorption was investigated. Results show that the dielectric constant further decrease up to 2.85. Some films were then annealed from 400 - 800 °C and it was found that the k for films deposited with higher [CH4] has a better stability with respect to annealing up to a temperature of 600 °C.


2008 ◽  
Vol 8 (5) ◽  
pp. 2680-2683 ◽  
Author(s):  
Hong-Hsin Huang

Nano-columnar TiO2 grains are prepared and immobilized by chemical vapor deposition using TiCl4, H2 and O2 at low temperature. The structure of TiO2 is analyzed by X-ray diffraction (XRD), the morphology is observed by scanning electron microscopy (SEM) and the adhesion is estimated by measuring the critical load in scratch test. Results show that the structure of TiO2 films depend on the deposition temperature changing from amorphous, anatase, rutile, and both anatase and rutile phases as prepared at temperatures of 200, 300, 400 and 500 °C, respectively. The nano-columnar TiO2 grains are formed in both rutile and anatase phases, while it could be only rutile phase by increasing TiCl4 flow rate. The morphologies of TiO2 changes from smooth to nano-columnar grains as the deposition temperature increased from 200 to 400 °C. Excellent adhesion strength of crystalline TiO2 was obtained and it could be improved by increasing the TiCl4 flow rate in range of 0.3–0.6 sccm, where the critical load of TiO2 increases from 17 to 21 N.


2001 ◽  
Vol 688 ◽  
Author(s):  
Hiroshi Funakubo ◽  
Kuniharu Nagashima ◽  
Masanori Aratani ◽  
Kouji Tokita ◽  
Takahiro Oikawa ◽  
...  

AbstractPb(Zr,Ti)O3 (PZT) is one of the most promising materials for ferroelectric random access memory (FeRAM) application. Among the various preparation methods, metalorganic chemical vapor deposition (MOCVD) has been recognized as a most important one to realize high density FeRAM because of its potential of high-step-coverage and large-area-uniformity of the film quality.In the present study, pulsed-MOCVD was developed in which a mixture of the source gases was pulsed introduced into reaction chamber with interval. By using this deposition technique, simultaneous improvements of the crystallinity, surface smoothness, and electrical property of the film have been reached by comparing to the conventional continuous gas-supplied MOCVD. Moreover, this film had larger remanent polarization (Pr) and lower leakage current density. This is owing to reevaporation of excess Pb element from the film and increase of migration on the surface of substrate during the interval time.This process is also very effective to decrease the deposition temperature of the film having high quality. In fact, the Pr and the leakage current density of polycrystalline Pb(Zr0.35Ti0.65)O3 film deposited at 415 °C were 41.4 μC/cm2 and on the order of 10−7 A/cm2 at 200 kV/cm. This Pr value was almost the same as that of the epitaxially grown film deposited at 415 °C with the same composition corrected for the orientation difference. This suggests that the polycrystalline PZT film prepared by pulsed-MOCVD had the epitaxial-grade ferroelectric properties even through the deposition temperature was as low as 415 °C. Moreover, large “process window” comparable to the process window at 580 °C, above 150 °C higher temperature and was widely used condition, was achieved even at 395°C by the optimization of the deposition condition.


2010 ◽  
Vol 25 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Cui-ying LU ◽  
Lai-fei CHENG ◽  
Li-tong ZHANG ◽  
Chun-nian ZHAO

2003 ◽  
Vol 799 ◽  
Author(s):  
Peng Lu ◽  
J. H. Edgar ◽  
J. Pomeroy ◽  
M. Kuball ◽  
H. M. Meyer ◽  
...  

ABSTRACTThe parameters necessary to deposit oriented rhombohedral boron phosphide (B12P2) thin films on on-axis Si-face 6H-SiC(0001) substrates by chemical vapor deposition are reported. Ultra high purity BBr3 and PBr3 were used as reactants, with hydrogen as the carrier gas. The BBr3 to PBr3 flow rate ratio was adjusted to obtain good surface morphology of the B12P2 films. BBr3 to PBr3 ratios in the range of 1 to 1.5 produced smooth surfaces and moderate growth rates of 10μm/hr. Higher growth rates were obtained by increasing the BBr3 flow rate, but the surfaces became very rough. The c-axis of the B12P2 film was aligned with the c -axis of the substrate at temperatures between 1650°C-1700°C. The surface morphologies were investigated by SEM and the crystalline properties of the films were characterized by XRD and Raman spectroscopy.


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