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}).

A Comparison of the Structural Quality of High-In Content InGaAsN Films Grown on InGaAs Pseudosubstrate and on GaAs Substrate

2007 ◽  
Vol 31 ◽  
pp. 221-223
Author(s):  
S. Sanorpim ◽  
P. Kongjaeng ◽  
R. Katayama ◽  
Kentaro Onabe
Keyword(s):  
Electron Microscopy ◽  
Gaas Substrate ◽  
Misfit Strain ◽  
The Other ◽  
Buffer Layers ◽  
Structural Quality ◽  
Misfit Dislocations ◽  
Transmission Electron ◽  
Lattice Matched

The use of an InGaAs buffer layer was applied to the growth of thick InxGa1-xAs1-yNy layers with higher In contents (x > 30%). In order to obtain the lattice-matched InGaAsN layer having the bandgap of 1.0 eV, the In0.2Ga0.8As was chosen. In this work, the In0.3Ga0.7As0.98N0.02 layers were successfully grown on closely lattice-matched In0.2Ga0.8As buffer layers (InGaAsN/InGaAs). Structural quality of such layers is discussed in comparison with those of the In0.3Ga0.7As0.98N0.02 layers grown directly on the GaAs substrate (InGaAsN/GaAs). Based on the results of transmission electron microscopy, the misfit dislocations (MDs), which are located near the InGaAsN/GaAs heteroepitaxial interface, are visible by their strain contrast. On the other hand, no generation of the MDs is evidenced in the InGaAsN layer grown on the In0.2Ga0.8As pseudosubstrate. Our results demonstrate that a reduction of misfit strain though the use of the pseudosubstrate made possible the growth of high In-content InGaAsN layers with higher crystal quality to extend the wavelength of InGaAsN material.

Cross-Sectional TEM Investigation of Low-Temperature Epitaxial Silicon Films Grown by Ultra-Low Pressure CVD

1986 ◽  
Vol 75 ◽  
Author(s):  
T. R. Yew ◽  
J. H. Comfort ◽  
L. M. Garverick ◽  
W. R. Burger ◽  
R. Reif
Keyword(s):  
Dislocation Density ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Epitaxial Films ◽  
Epitaxial Silicon ◽  
Cross Sectional ◽  
Dislocation Densities ◽  
Pressure Chemical

AbstractIn this paper, cross-sectional TEM is used to investigate the quality of silicon epitaxial films grown by ultra-low pressure chemical vapor deposition at 750°C. The dislocation density and epi.- substrate interface width were investigated for different predeposition Argon sputter cleaning condltions. Epitaxial films with dislocation densities of less than 10 cm−2 and interfacial width of about 13 Å were obtained.

The Use of Tertiarybutylphosphine and Tertiarybutylarsine for the Metalorganic Molecular Beam Epitaxial Growth of Resonant Tunneung Devices

1991 ◽  
Vol 240 ◽  
Author(s):  
E. A. Beam ◽  
A. C. Seabaugh
Keyword(s):  
Resonant Tunneling ◽  
Growth Conditions ◽  
Structural Quality ◽  
Cross Sectional ◽  
Molecular Beam Epitaxial ◽  
Tunneling Diode ◽  
Transmission Electron ◽  
Molecular Beam Epitaxial Growth ◽  
First Time ◽  
Lattice Matched

ABSTRACTWe report on the use of thermally-cracked tertiarybutylphosphine (TBP) and tertiarybutylarsine (TBA) with elemental Ga, In, and Al sources for the MOMBE growth of InP-based resonant tunneling diode (RTD) and resonant tunneling bipolar transistor (RTBT) structures. We have systematically examined the effects of growth conditions and heterostructure modifications on the InP/lnGaAs RTD including the use of pseudomorphic (InGa)P barriers and, in addition, explored for the first time, InP quantum well RTDs using both AlAs and InGaP barriers. Cross-sectional transmission electron microscopy has been used to correlate the structural quality with the electrical characteristics for both lattice-matched and pseudomorphic layers composed of InAs, AlAs, and InGaP. We also demonstrate the first use of mixed InP/lnGaAs and AlAs/lnGaAs heterojunctions in the RTBT. These transistors exhibit room temperature negative transconductance and a peak-to-valley current ratio of 35, the highest yet observed In the RTBT.

scholarly journals Microstructures of GaN and InxGa1-xN Films Grown by MOCVD on freestanding GaN Templates

2002 ◽  
Vol 722 ◽  
Author(s):  
J. Jasinski ◽  
Z. Liliental-Weber ◽  
D. Huang ◽  
M. A. Reshchikov ◽  
F. Yun ◽  
...  
Keyword(s):  
Lattice Parameter ◽  
Point Of View ◽  
Structural Quality ◽  
Threading Dislocations ◽  
Structural Studies ◽  
Transmission Electron ◽  
Nitride Layers ◽  
Convergent Beam ◽  
Gan Film

AbstractWe summarize structural properties of thick HVPE GaN templates from the point of view of their application as substrates for growth of nitride layers. This is followed by the results of optical and structural studies, mostly transmission electron microscopy, of nitride layers grown by MOCVD on top of the HVPE substrates. The results indicate high structural quality of these layers with a low density of threading dislocations (in the range of 106 cm-2). Convergent beam electron diffraction studies showed that the MOCVD GaN films have Ga-polarity, the same polarity as the HVPE GaN substrates. Structural studies of an InGaN layer grown on top of the MOCVD GaN film showed the presence of two layers, which differed in lattice parameter and composition. The upper layer, on the top of the structure had a clattice parameter about 2 % larger than that of GaN and contained 10.3 ± 0.8 % of In. Values measured for the thinner, intermediate layer adjacent to the GaN layer were about 2.5 times lower.

MOCVD Growth of GaN on bulk AlN Substrates

1997 ◽  
Vol 482 ◽  
Author(s):  
Hong-Qiang Lu ◽  
Ishwara B. Bhat ◽  
Byung-Chan Lee ◽  
Glen A. Slack ◽  
Leo J. Schowalter
Keyword(s):  
Low Temperature ◽  
Preparation Method ◽  
Surface Preparation ◽  
The Other ◽  
Substrate Orientation ◽  
Exciton Emission ◽  
Plane Orientation ◽  
Mocvd Growth ◽  
Polishing Damage

AbstractIn this paper, the growth of epitaxial GaN layers on c-plane and a-plane bulk AIN substrates by metalorganic vapor phase epitaxy is reported. The AlN boules were grown by the sublimationrecondensation technique. Single crystal GaN films grown on the c-plane orientation replicate the substrate orientation. However the surface of the epilayer had a high density of cross-hatch defect lines, presumably caused by mechanical polishing damage. The low temperature PL spectra of these films were dominated by exciton emission at 3.470 eV with a FWHM of 14 meV at 7 K. On the other hand, GaN grown on the a-plane orientation AlN was polycrystalline and the surface was rough with ridge-like facets. The PL from this film showed a dominate peak at 3.406 eV which may originate from defect-bound excitons. The quality of the GaN layers grown on these AIN bulk substrates appeared to be limited by the surface preparation method, which has not been optimized.

scholarly journals Influence of substrate misorientation on the structural quality of lattice matched GaAs/ScYbAs/GaAs structures

1992 ◽  
Vol 3 (4) ◽  
pp. 299-312 ◽  
Author(s):  
Béatrice Guenais ◽  
Alain Poudoulec ◽  
André Guivarc'h ◽  
Yves Ballini ◽  
Vincent Durel ◽  
...  
Keyword(s):  
Structural Quality ◽  
Influence Of Substrate ◽  
Lattice Matched

Near Defect Free GaN Substrates

1998 ◽  
Vol 537 ◽  
Author(s):  
S. Porowski
Keyword(s):  
Nitrogen Pressure ◽  
Current Status ◽  
Structural Quality ◽  
Growth Mechanisms ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Homoepitaxial Layers ◽  
Atomically Flat ◽  
Mg Doped

AbstractThe current status of GaN crystallization under high nitrogen pressure will be presented. Both conductive and semi-insulating GaN crystals will be characterized.In particular the influence of Mg on the growth mechanisms will be discussed. The influence of Mg doping on morphology of Mg-doped crystals grown under pressure and Mg-doped homoepitaxial layers will be shown. It will be also shown that the addition of about I at.% of Mg into the solution improves significantly the structural quality of crystals reducing dislocation density at least by 3 orders of magnitude comparing to the crystals grown without an intentional doping. As it was estimated by selective wet etching and transmission electron microscopy the dislocation densities in the Mg-doped GaN is as low as 10 cm-1. The introduction of Mg also lowers the optical absorption coefficients for energies below fundamental edge by 2 to 3 orders of magnitude what is explained by disappearance of defect related states in the gap.The procedures for preparation of atomically flat epi-ready (000 1 ) surfaces without subsurface damage will be described. It will be shown that high quality homoepitaxial layers growing by monoatomic steps are possible on these substrates.

Sign in / Sign up

Export Citation Format

Share Document