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MOVPE Growth (movpe + growth)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

MOVPE growth and characterization of a -plane AlGaN over the entire composition range

PHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 7 2010
Masihhur R. Laskar
Abstract We report the metal organic vapor phase epitaxy (MOVPE) growth and characterization of non-polar (110) a -plane Alx Ga1,xN on (102) r -plane sapphire substrates over the entire composition range. Alx Ga1,xN samples with ,0.8 ,m thick layers and with x = 0, 0.18, 0.38, 0.46, 0.66, and 1.0 have been grown on r -plane sapphire substrates. The layer quality can be improved by using a 3-stage AlN nucleation layer and appropriate V/III ratio switching following nucleation. All a -plane AlGaN epilayers show an anisotropic in-plane mosaicity, strongly influenced by Al incorporation and growth conditions. Careful lattice parameter measurements show anisotropic in-plane strain that results in an orthorhombic distortion of the hexagonal unit cell, making Al composition determination from X-ray diffraction difficult. In general lower Al incorporation is seen in a -plane epilayers compared to c -plane samples grown under the same conditions. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Three-dimensionally structured silicon as a substrate for the MOVPE growth of GaN nanoLEDs

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2009
Sönke Fündling
Abstract Three-dimensionally patterned Si(111) substrates are used to grow GaN based heterostructures by metalorganic vapour phase epitaxy, with the goal of fabricating well controlled, defect reduced GaN-based nanoLEDs. In contrast to other approaches to achieve GaN nanorods, we employed silicon substrates with deep etched nanopillars to control the GaN nanorods growth by varying the size and distance of the Si pillars. The small footprint of GaN nanorods grown on Si pillars minimise the influence of the lattice mismatched substrate and improve the material quality. For the Si pillars an inductively coupled plasma dry-etching process at cryogenic temperature has been developed. An InGaN/GaN multi quantum well (MQW) structure has been incorporated into the GaN nanorods. We found GaN nanostructures grown on top of the silicon pillars with a pyramidal shape. This shape results from a competitive growth on different facets as well as from surface diffusion of the growth species. Spatially resolved optical properties of the structures are analysed by cathodoluminescence. Strongly spatial-dependent MQW emission spectra indicate the growth rate differences on top of the rods. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

MOVPE growth and optical characterization of GaAsN films with higher nitrogen concentrations

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2006
F. Nakajima
Abstract We have successfully grown high-N-content GaAsN films up to 5.1% on GaAs(001) substrates using tertiarybutylarsine (TBAs) as the As precursor by metalorganic vapour phase epitaxy (MOVPE). The narrow X-ray diffraction (XRD) peaks and clear Pendellosung fringes indicate that the GaAsN/GaAs interface is fairly flat and the GaAsN layers are uniform. By the photoluminescence (PL) measurement at 10 K, the clear PL peaks related to the near-band-edge transition could be detected and the bandgap energy was red-shifted to 1.16 eV in 1.9%-N GaAsN film. But, in higher N-content films no peak could be detected. So, post growth annealing in the reactor was applied to 4.7% and 5.1%-N films, and resulted in an enhancement of the PL peak intensity, and the bandgap energy of 5.1%-N film was consequently determined to be 0.95 eV at room temperature. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Growth of GaN on a -plane sapphire: in-plane epitaxial relationships and lattice parameters

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2003
T. Paskova
Abstract We have studied GaN films grown on a -plane sapphire substrates by both hydride vapor phase epitaxy (HVPE) and metalorganic vapor phase epitaxy (MOVPE). The in-plane orientation relationships between the epitaxial films and the substrate are determined to be [11,20]GaN , [0001]sapphire and [1,100]GaN , [1,100]sapphire in the HVPE growth, while [1,100]GaN , [0001]sapphire and [11,20]GaN , [1,100]sapphire are found in the MOVPE growth. The different orientation preferences are attributed to the atom termination of the sapphire surface determined by the substrate treatment used in the different growth methods. The effect of the lattice matches on the in-plane lattice parameters and strain anisotropy in the two cases is studied. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Atmospheric-pressure MOVPE growth of In-rich InAlN

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2008
Y. Houchin
Abstract This paper reports the atmospheric-pressure MOVPE growth of In-rich InAlN. All InAlN films prepared here (Al content:0, 0.43) do not show phase separation. The incorporation of Al in InAlN is decreased with increasing growth temperature. A decrease in Al content is also observed for films grown at a position farther from the up-stream end of the susceptor. The marked decrease in the Al content along the gas flow direction seems to be caused by the shortage of TMA supply at the downstream by the parasitic reaction of TMA. A single-crystalline InAlN film with an Al content of 0-0.43 is successfully grown by adjusting growth temperature and TMA/(TMI+TMA) molar ratio. FWHM of X-ray rocking curve for InAlN is increased with increasing Al content. The carrier concentrations in InAlN films are comparable to that in InN (1-5 × 1019 cm,3). All the single-crystalline InAlN films with an Al content of 0-0.3 show a photoluminescence at room temperature. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Adduct formation of CP2Mg with NH3 in MOVPE growth of Mg-doped InN

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2007
Y. Nagai
Abstract The Mg doping for MOVPE InN has been studied using biscyclopentadienyllmagnesium CP2Mg as a Mg source. The InN samples grown near the upstream end of the 18 cm long susceptor have very small grain size and contain a high level of C and H contamination. The XPS analysis of the deposits obtained by the supply of CP2Mg together with NH3 reveals that new Mg compounds are formed near the upstream end of the susceptor. The new compounds are adducts of CP2Mg and NH3, because they can not be formed when only CP2Mg is supplied. The adduct formation seems to be a cause for the very small grain size and the high levels of C and H contamination. The adduct formation is suppressed at positions with a distance more than 9 cm from the upstream end. This means that designs of reactor and susceptor are very important for successful Mg doping of InN with CP2Mg. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Thermodynamic aspects of carbon incorporation into AlN epitaxial layers grown by MOVPE

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2005
J. Leitner
Abstract Thermodynamic aspects of carbon incorporation into AlN during the MOVPE growth are discussed. Under low potential in the gaseous phase, carbon dissolves in AlN substituting nitrogen atoms. A sublattice model has been proposed to describe the thermodynamic behavior of this pseudobinary solution AlN-C. When carbon potential increases, solid graphite is formed simultaneously to AlN. At V/III input ratio (V/III = x/x) lower than one, carbonitride Al5C3N as well carbide Al4C3 can be formed. The calculated results are compared with the composition of AlN layers growth by MOVPE. The serious discrepancies exist which can be explained by the crude nature of the solution model as well as by non-equilibrium conditions during the MOVPE growth and subsequent carbon supersaturation of the resulting layers. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]