Structural Defects in GaN Epilayers Grown by Gas Source Molecular Beam Epitaxy

1989 ◽  
Vol 162 ◽  
Author(s):  
Z. Sitar ◽  
M. J. Paisley ◽  
B. Yan ◽  
R. F. Davis
Keyword(s):  
Electron Cyclotron Resonance ◽  
Plasma Source ◽  
Structural Defects ◽  
Effusion Cell ◽  
Gas Source ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Gas Source Mbe ◽  
Inversion Domain Boundaries ◽  
Resonance Plasma

ABSTRACTSingle crystal cubic or hexagonal GaN thin films have been grown on various substrates, using a modified gas source MBE technique. A standard effusion cell was employed for the evaporation of gallium. A compact electron cyclotron resonance plasma source was used to activate the nitrogen prior to deposition. The films were examined by transmission electron microscopy. The major defects in the wurtzite GaN were double positioning boundaries, inversion domain boundaries, and dislocations. The zinc-blende GaN showed microtwins, stacking faults, and dislocations. The connection between the observed structural defects and the poor electrical properties of GaN is noted.

Epitaxial growth of AlN by plasma-assisted, gas-source molecular beam epitaxy

1993 ◽  
Vol 8 (9) ◽  
pp. 2310-2314 ◽  
Author(s):  
L.B. Rowland ◽  
R.S. Kern ◽  
S. Tanak ◽  
Robert F. Davis
Keyword(s):  
Molecular Beam Epitaxy ◽  
Epitaxial Growth ◽  
Cyclotron Resonance ◽  
Molecular Beam ◽  
Electron Cyclotron Resonance ◽  
Plasma Source ◽  
Effusion Cell ◽  
Nitrogen Species ◽  
Gas Source ◽  
Resonance Plasma

Monocrystalline AlN(0001) films with few defects were deposited on vicinal α(6H)–SiC(0001) wafers via plasma-assisted, gas-source molecular beam epitaxy within the temperature range of 1050–1200 °C. The Al was thermally evaporated from an effusion cell. An electron cyclotron resonance plasma source was used to produce activated nitrogen species. Growth on vicinal Si(100) at 900–1050 °C resulted in smooth, highly oriented AlN(0001) films.

Structure and Morphology Characters of GaN Grown by ECR-MBE Using Hydrogen-Nitrogen Mixed Gas Plasma

1999 ◽  
Vol 595 ◽  
Author(s):  
Tsutomu Araki ◽  
Yasuo Chiba ◽  
Yasushi Nanishi
Keyword(s):  
Cyclotron Resonance ◽  
Molecular Beam ◽  
Electron Cyclotron Resonance ◽  
The Other ◽  
Mixed Gas ◽  
Structure And Morphology ◽  
Gas Plasma ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Resonance Plasma

AbstractGaN growth by electron-cyclotron-resonance plasma-excited molecular beam epitaxy using hydrogen-nitrogen mixed gas plasma were carried out on GaN templates with a different polar-surface. Structure and surface morphology of the GaN layers were characterized using transmission electron microscopy. The GaN layer grown with hydrogen on N-polar template showed a relatively flat morphology including hillocks. Columnar domain existed in the center of the hillock, which might be attributed to the existence of tiny inversion domain with Ga-polarity. On the other hand, columnarstructure was formed in the GaN layer grown with hydrogen on Ga-polar template.

Effects of Stress-relieving AlN Interlayers in GaN-on-Si Grown by Plasma-assisted Molecular Beam Epitaxy

2008 ◽  
Vol 1068 ◽  
Author(s):  
Adam Adikimenakis ◽  
Suman-Lata Sahonta ◽  
George Dimitrakopulos ◽  
Jaroslav Domagala ◽  
Philomela Komninou ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Plasma Source ◽  
Rf Plasma ◽  
X Ray Diffraction ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Stress Relieving ◽  
Gan On Si ◽  
Inversion Domain Boundaries

ABSTRACTThe insertion of an AlN interlayer for tensile strain relief in GaN thin films grown on Si (111) on-axis and vicinal substrates by nitrogen rf plasma source molecular beam epitaxy has been investigated. The 15 nm AlN interlayer was inserted between the bottom 0.5 micron GaN layer and the top 1.0 micron GaN layer. The interlayer was very effective to reduce the tensile stress in the overall 1.5 micron GaN/Si film to the level required for complete avoidance of microcracks, which were present in high densities in GaN/Si heterostructures grown without an AlN interlayer. The strain of the AlN interlayer, as well as the strain in all the layers of the entire GaN/Si heterostructure was analyzed by x-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements. Reciprocal space map in XRD indicated that the 15 nm AlN interlayer was coherently strained with the GaN films. However TEM observations revealed that the AlN interlayer was partially relaxed in local regions. The AlN interlayer was also observed to interfere with the GaN growth process. In particular, above morphological features such as V-defects, GaN was overgrown with a large density of threading dislocations and inversion domain boundaries.

Microstructral Investigations on GaN Films Grown by Laser Induced Molecular Beam Epitaxy

1999 ◽  
Vol 595 ◽  
Author(s):  
H. Zhou ◽  
F. Phillipp ◽  
M. Gross ◽  
H. Schröder
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Threading Dislocations ◽  
Planar Defects ◽  
Sapphire Substrates ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Line Defects ◽  
Inversion Domain Boundaries

AbstractMicrostructural investigations on GaN films grown on SiC and sapphire substrates by laser induced molecular beam epitaxy have been performed. Threading dislocations with Burgers vectors of 1/3<1120>, 1/3<1123> and [0001] are typical line defects, predominantly the first type of dislocations. Their densities are typically 1.5×1010 cm−2 and 4×109 cm−2 on SiC and sapphire, respectively. Additionally, planar defects characterized as inversion domain boundaries lying on {1100} planes have been observed in GaN/sapphire samples with an inversion domain density of 4×109 cm−2. The inversion domains are of Ga-polarity with respect to the N-polarity of the adjacent matrix. However, GaN layers grown on SiC show Ga-polarity. Possible reasons for the different morphologies and structures of the films grown on different substrates are discussed. Based on an analysis of displacement fringes of inversion domains, an atomic model of the IDB-II with Ga-N bonds across the boundary was deduced. High resolution transmission electron microscopy (HRTEM) observations and the corresponding simulations confirmed the IDB-II structure determined by the analysis of displacement fringes.

Structure and Magnetic Properties of Fe-N Thin Films Grown by ECR Deposition

1999 ◽  
Vol 562 ◽  
Author(s):  
Š émeth ◽  
H. Akinaga ◽  
H. Boeve ◽  
H. Bender ◽  
J. de Boeck ◽  
...  
Keyword(s):  
Thin Films ◽  
Electron Cyclotron Resonance ◽  
Microwave Plasma ◽  
Nitrogen Concentration ◽  
High Vacuum ◽  
Plasma Source ◽  
Columnar Structure ◽  
Ultra High Vacuum ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTThe growth of FexNy thin films on GaAs, In0.2Ga0.8As, and SiO2/Si substrates using an ultra high-vacuum (UHV) deposition chamber equipped with electron cyclotron resonance (ECR) microwave plasma source is presented. The structural properties of the deposited films have been measured using various techniques as x-ray diffraction (XRD), Auger electron spectroscopy (AES), and transmission electron microscopy (TEM). The results of XRD measurements show that the films consist of a combination of α-Fe, α'-Fe, y-Fe4N, and α”- Fe16N2 phases. The depth profiles, calculated from the Auger peak intensities, show a uniform nitrogen concentration through the films. The TEM reveals a columnar structure of these films. The properties of the different Fe-N layers have been exploited in the fabrication of Fe(N) / FexNy / Fe trilayer structures, where Fe(N) means a slightly nitrogen doped Fe film. The magneto-transport properties of this trilayer structure grown on In0.2Ga0.8As substrates are presented.

Inversion Domain Boundaries in GaN Grown on Sapphire

1996 ◽  
Vol 449 ◽  
Author(s):  
L. T. Romano ◽  
J.E. Northrup
Keyword(s):  
Dark Field ◽  
Hydride Vapor Phase Epitaxy ◽  
Dark Field Imaging ◽  
Inversion Domain ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Convergent Beam ◽  
Inversion Domain Boundaries ◽  
Field Imaging ◽  
Beam Diffraction

ABSTRACTInversion domain boundaries (IDBs) in GaN grown on sapphire (0001) were studied by a combination of high resolution transmission electron microscopy, multiple dark field imaging, and convergent beam diffraction. Films grown by molecular beam epitaxy (MBE), metalorganic vapor deposition (MOCVD), and hydride vapor phase epitaxy (HVPE) were investigated and all found to contain IDBs. Inversion domains (IDs) that extended from the surface to the interface were found to be columnar with facets on the {10–10} and {11–20} planes. Other domains ended within the film that formed IDBs on the (0001) and {1–102} planes. The domains were found to grow in clusters and connect at points along the boundary.

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