Effect of Substrate Orientation on CdTe Film Growth by OMVPE

1990 ◽  
Vol 216 ◽  
Author(s):  
D.W. Snyder ◽  
E.I. Ko ◽  
S. Mahajan ◽  
P.J. Sides
Keyword(s):  
Surface Morphology ◽  
Deposition Rate ◽  
Deposition Temperature ◽  
Film Growth ◽  
Cdte Film ◽  
Structural Quality ◽  
Substrate Orientation

ABSTRACTMost CdTe epilayers grown by OMVPE have been deposited on two low index orientations: {111}Te and {100}. In this study we have examined the OMVPE of CdTe as a function of deposition temperature on CdTe substrates having the four low index orientations ({111}Te, P111}Cd, {110}, and {100}) and on the {211}Te and {211}Cd orientations. Results are presented for deposition rate, surface morphology, and structural quality of the epilayers.

Magnetic Anisotropy of Strained La0.7Sr0.3MnO3 Thin Films Studied by MOKE

2001 ◽  
Vol 690 ◽  
Author(s):  
M. Koubaa ◽  
A.M. Haghiri-Gosnet ◽  
P. Lecoeur ◽  
W. Prellier ◽  
B. Mercey
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Scaling Law ◽  
Hysteresis Loops ◽  
Magnetic Behavior ◽  
Growth Conditions ◽  
Structural Quality ◽  
Lattice Strains ◽  
Stress States

ABSTRACTThe effects of the growth conditions and the lattice strains of pulsed laser deposited (PLD) La0.7Sr0.3MnO3 (LSMO) thin films upon the magnetic behavior have been studied using magneto-optical Kerr effect (MOKE) at room temperature. First, the structural quality of the films was investigated by XRD and the surface morphology was studied using AFM. It is shown that both surface morphology and crystallinity are optimized when the target-to-substrate distance and the oxygen pressure are chosen in agreement with a PD3 scaling law. Secondly, hysteresis loops have been recorded along the [100], [110] and [001] directions and the easy directions of magnetization have been determined for both stress states, i.e. tension on SrTiO3 and compression on LaAlO3. In tensile films, the whole plane is found to be easy, whereas, in compressive films, the easy axis should be an intermediate direction between the film's plane and its normal. Moreover, tensile films deposited under optimized growth conditions exhibit the largest anisotropy coefficient (K1eff = -6.9×105 erg/cm3).

scholarly journals Morphology and surface reconstructions of m-plane GaN

2002 ◽  
Vol 743 ◽  
Author(s):  
C. D. Lee ◽  
R. M. Feenstra ◽  
J. E. Northrup ◽  
L. Lymperakis ◽  
J. Neugebauer
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Surface Morphology ◽  
Buffer Layer ◽  
Molecular Beam ◽  
Structural Quality ◽  
Surface Reconstructions ◽  
Gan Buffer Layer

ABSTRACTM-plane GaN(1100) is grown by plasma assisted molecular beam epitaxy on ZnO(1100) substrates. A low-temperature GaN buffer layer is found to be necessary to obtain good structural quality of the films. Well oriented (1100) GaN films are obtained, with a slate like surface morphology. On the GaN(1100) surfaces, reconstructions with symmetry of c(2×2) and approximate “4×5” are found under N- and Ga-rich conditions, respectively. We propose a model for Ga-rich conditions with the “4×5” structure consisting of ≥ 2 monolayers of Ga terminating the GaN surface.

High-Speed Deposition of SiC Thick Film by Halide Precursor

2014 ◽  
Vol 616 ◽  
pp. 37-42 ◽  
Author(s):  
Ming Xu Han ◽  
Wei Zhou ◽  
Ding Heng Zheng ◽  
Rong Tu ◽  
Song Zhang ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Thick Film ◽  
Deposition Rate ◽  
Deposition Temperature ◽  
High Speed ◽  
Gaseous Mixture ◽  
Chemical Vapor ◽  
Preferred Orientation ◽  
Graphite Substrate ◽  
Deposition Effect

Polycrystalline ڂ˽SiC thick film with mm-scaled thickness was deposited on a graphite substrate using a gaseous mixture of SiCl4 + CH4 and H2 at temperatures ranging from 1573 to 1823 K by chemical vapor deposition. Effect of deposition temperature (Tdep) on deposition rate, surface morphology and preferred orientation has been studied. The preferred orientation changed from <111> to <110> with increasing Tdep. The maximum deposition rate (Rdep) of 1125 ڌ̽˰̸−1 has been obtained. The surface morphology has changed from six-fold pyramid to five-fold facet with increasing Tdep.

MOCVD Growth of GaN Films on Lattice-Matched Oxide Substrates

1996 ◽  
Vol 449 ◽  
Author(s):  
O. M. Kryliouk ◽  
T. W. Dann ◽  
T. J. Anderson ◽  
H. P. Maruska ◽  
L. D. Zhu ◽  
...  
Keyword(s):  
Structural Quality ◽  
Film Properties ◽  
Cross Sectional ◽  
Substrate Orientation ◽  
Mocvd Growth ◽  
Dislocation Densities ◽  
Oxide Substrates ◽  
Lattice Matched ◽  
Gan Film

ABSTRACTThe use of the nearly lattice-matched oxide substrates LiGaO2 and LiAlO2 has been explored for growth of GaN by MOCVD. As compared to the quality of films grown on sapphire, only growth on LiGaO2 yielded good quality films, and required use of nitrogen as the carrier gas. Furthermore, high structural quality films were grown on LiGaO2 at temperatures as low as 850°C. Dislocation densities estimated from cross-sectional TEM micrographs were found to be as low as 107 cm-2 . HRTEM studies revealed deformations at the surface of the LiGaO2 adjacent to deposited GaN films, indicating possible interracial reactions which may affect the film properties. The GaN film orientations corresponded directly to the substrate orientation, viz., ({0001}/{001} and {1102}/{101}).

Mocvd of Copper from the Solution of New and Liquid Precursor (hfac)Cu(1-pentene)

1998 ◽  
Vol 514 ◽  
Author(s):  
H.-K. Shin ◽  
Y.-H. Cho ◽  
D.-J. Yoo ◽  
H.-J. Shin ◽  
E.-S. Lee
Keyword(s):  
Surface Morphology ◽  
Deposition Rate ◽  
Deposition Temperature ◽  
Pure Copper ◽  
Copper Films ◽  
Vapor Pressures ◽  
Dynamic Vacuum ◽  
Liquid Precursor ◽  
Temperature Range

ABSTRACTIn an attempt to increase the deposition rate, new Cu (I) compounds, (hfac)Cu(1-pentene)(1) and (hfac)Cu(VTMOS)(2) have been synthesized. These species are chartreuse liquids and exhibit sufficient vapor pressures to allow high transport rates.In order to avoid the premature decomposition of the copper precursors during CVD processes, the 50% of free 1-pentene, and VTMOS was added to the compounds 1 and 2 respectively. These mixtures 1 and 2 were used in this study. Approximately 2gm of precursor was used for each experiment. No premature decomposition of the precursor in the source reservoir was observed during CVD processes. It is a sufficiently important result to expect the use of these mixtures in copper CVD to achieve the reproducible deposition.The copper films using these mixtures were deposited in a hot-wall pyrex reactor at a pressure of approximately 10–2 torr under dynamic vacuum. The films deposited at 100°C, 150°C and 200°C from the mixture 1. Pure copper films were deposited from these species. The resistivities 1.8 ∼ 2.1 μΩcm were obtained in the deposition temperature range. SEM revealed that the surface morphology of the films grown in these depositon temperature range was composed of dense film and grains were well connected. The deposition rate at 200°C was 3,500 Å/min.

Deposition Rate Effect of Alq3 Thin Film Growth: A Kinetic Monte Carlo Study

2008 ◽  
Vol 61 (8) ◽  
pp. 600
Author(s):  
Yih-Jiun Lin ◽  
Jian-Chuang Chang ◽  
Chin-Kuen Tai ◽  
Bo-Cheng Wang ◽  
Feng-Yin Li
Keyword(s):  
Thin Film ◽  
Monte Carlo ◽  
Surface Morphology ◽  
Deposition Rate ◽  
Film Growth ◽  
Kinetic Monte Carlo ◽  
Young Scientist ◽  
Film Surface ◽  
Monte Carlo Study ◽  
Island Growth

This paper is the winner of the Young Scientist Award at the Asian Chemical Congress in Kuala Lumpur, 2007. Applying the Kinetic Monte Carlo (KMC) technique, we successfully investigated the effect of deposition rate on the growth pattern of an Alq3 thin film. In good agreement with experimental results, our simulation results indicate that there exists a transition growth in terms of the deposition rate that corresponds to the transition between the island growth and random deposition growth. In the regions of island growth (where the deposition rate is lower than 1.1 Å s–1) and random deposition growth (where the deposition rate is higher than 3 Å s–1), the surface morphology is not suitable for luminant devices because of a high roughness, a larger inner vacancy ratio at higher deposition rate, and low homogeneity at lower deposition rate conditions. Within the transition growth region (deposition rate is between 1.1 and 3.0 Å s–1), the homogeneity of the film surface improves as the deposition rate increases. Not only does the pattern of the island structures become blurred, but the inner vacancy ratio and surface roughness also remain low as the deposition rate increases. From our results, there may exist a deposition rate to optimize the Alq3 film with a suitable surface morphology for luminant devices.

Effects of Susceptor Geometry on GaN Growth on SI(111) with a New Mocvd Reactor

1998 ◽  
Vol 537 ◽  
Author(s):  
Yungeng Gao ◽  
Daniel A. Gulino ◽  
Ryan Higgins
Keyword(s):  
Single Crystal ◽  
Film Growth ◽  
Chemical Species ◽  
Buffer Layers ◽  
Structural Quality ◽  
Growth Pressure ◽  
Rocking Curve ◽  
X Ray ◽  
Mocvd Reactor

AbstractHigh quality GaN films on AIN buffer layers were grown on Si(111) with a new, commercial, two-injector vertical rotating disk MOCVD reactor (CVD, Inc.). It was found that the geometry of the susceptor greatly affected the structural quality of the epilayers on Si. For the original susceptor geometry, though single crystal GaN films could be obtained, the films were dark gray in appearance with a rough morphology, and the best x-ray rocking curve FWHM was 2.33°. After modifying the susceptor geometry, transparent, mirror-like single crystal GaN films were obtained with the best x-ray rocking curve FWHM being 0.24°. Photoluminescence (PL) and infrared reflectance (IR) spectra of the grown films were compared. The film growth rate was found to increase with decrease of the growth pressure. A 2-D simulation of the flow, heat transfer, and chemical species transport in the reactor showed a more symmetric flow, larger velocity gradient, and lower upward velocity with the modified susceptor, which may be the main reason for the improvement of the structural quality of the films.

scholarly journals Effects of Susceptor Geometry on Gan Growth on Si(111) with a New MOCVD Reactor

1999 ◽  
Vol 4 (S1) ◽  
pp. 316-321 ◽  
Author(s):  
Yungeng Gao ◽  
Daniel A. Gulino ◽  
Ryan Higgins
Keyword(s):  
Single Crystal ◽  
Film Growth ◽  
Chemical Species ◽  
Buffer Layers ◽  
Structural Quality ◽  
Growth Pressure ◽  
Rocking Curve ◽  
X Ray ◽  
Mocvd Reactor

High quality GaN films on AlN buffer layers were grown on Si(111) with a new, commercial, two-injector vertical rotating disk MOCVD reactor (CVD, Inc.). It was found that the geometry of the susceptor greatly affected the structural quality of the epilayers on Si. For the original susceptor geometry, though single crystal GaN films could be obtained, the films were dark gray in appearance with a rough morphology, and the best x-ray rocking curve FWHM was 2.33°. After modifying the susceptor geometry, transparent, mirror-like single crystal GaN films were obtained with the best x-ray rocking curve FWHM being 0.24°. Photoluminescence (PL) and infrared reflectance (IR) spectra of the grown films were compared. The film growth rate was found to increase with decrease of the growth pressure. A 2-D simulation of the flow, heat transfer, and chemical species transport in the reactor showed a more symmetric flow, larger velocity gradient, and lower upward velocity with the modified susceptor, which may be the main reason for the improvement of the structural quality of the films.

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