Morphology and Interface chemistry of the Initial Growth of GAN and ALN on α-SIC and Sapphire

1991 ◽  
Vol 237 ◽  
Author(s):  
Z. Sitar ◽  
L. S. Smith ◽  
M. J. Paisley ◽  
R. F. Davis
Keyword(s):  
Molecular Nitrogen ◽  
Three Dimensional ◽  
Plasma Source ◽  
Layer By Layer ◽  
Initial Growth ◽  
Interface Chemistry ◽  
Ecr Plasma ◽  
Gas Source ◽  
Nitride Formation ◽  
Gas Source Mbe

ABSTRACTThe morphology and interface chemistry occurring during the initial stages of growth of GaN and A1N layers has been obtained. Films were grown using gas source MBE equipment containing an ECR plasma source to activate molecular nitrogen. The experiments consisted of sequential depositions of about one monolayer thick films and XPS analysis. Evidence for silicon nitride formation on the SiC surface was obtained from the studies of both the Si oxidation states and the substrate peak intensity dependence on film thickness. The growth of GaN on sapphire appeared to occur via the Stranski-Krastanov mode, while the growth on SiC showed characteristics of three-dimensional growth. AlN grew in a layer-by-layer mode on both substrates.

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.

Layer-by-layer growth mechanism of AlxGa1-xP grown by gas-source MBE

1993 ◽  
Vol 127 (1-4) ◽  
pp. 213-216 ◽  
Author(s):  
Toshinari Fujimori ◽  
Satoru Nagao ◽  
Hideki Gotoh
Keyword(s):  
Growth Mechanism ◽  
Layer Growth ◽  
Layer By Layer ◽  
Gas Source ◽  
Gas Source Mbe

Initial Stages of Growth of Thin Films of III-V Nitrides and Silicon Carbide Polytypes by Molecular Beam Epitaxy

1994 ◽  
Vol 339 ◽  
Author(s):  
Robert F. Davis ◽  
K. S. Ailey ◽  
R. S. Kern ◽  
D. J. Kester ◽  
Z. Sitar ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Interface Chemistry ◽  
Stages Of Growth ◽  
Final Layer ◽  
Metal Evaporation ◽  
Dimensional Growth ◽  
Initial Deposition ◽  
Substrate Surfaces

ABSTRACTThe morphology and interface chemistry occurring during the initial deposition of BN, AlN and GaN films via metal evaporation and N2 decomposition under UHV conditions have been determined. FTIR spectroscopy and TEM revealed the consecutive deposition of an initial 20Å layer of a-BN, 20–60Å of oriented h-BN, and a final layer of polycrystalline c-BN. This sequence is attributed primarily to increasing intrinsic compressive stress in the films. XPS analysis revealed the growth of GaN on sapphire to occur via the Stranski-Krastanov mode; growth on SiC showed characteristics of three-dimensional growth. AlN grew layer-by-layer on both substrates. Vicinal 6H-SiC(0001) substrate surfaces contain closely spaced, single bilayer steps. During deposition of Si and C at 1050°C, 6H layers initially form and step bunching occurs. The latter phenomenon results in more widely spaced steps, the nucleation of 3C-SiC both on the new terraces and at the larger steps and formation of double position boundaries. The C/Si ratio in the gaseous reactants also affects the occurrence of these three phenomena.

Limitation of Selective Epitaxial Growth Conditions in Gas Source MBE Using Si2H6

1990 ◽  
Vol 204 ◽  
Author(s):  
Junro Sakai ◽  
Ken-Ichi Aketagawa ◽  
Toru Tatsumi
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Native Oxide ◽  
Initial Growth ◽  
Selective Epitaxial Growth ◽  
Gas Source ◽  
Gas Source Mbe

ABSTRACTLow temperature and high growth rate selective epitaxial growth (SEG) on Si02 patterned Si (001) substrate in gas-source molecular-beam epitaxy (GS-MBE) using pure Si2H6 has been investigated by RHEED observation. In the temperature range of 550 to 850°C, SEG was completely obtained at an initial growth stage. Limiting conditions of SEG were closely related with critical volume of supply gas that was equal to the total amount molecules supplied on SiO2 surface during the incubation period of initial growth. The surface SiO2 was induced to evaporate with Si2H6 supplied above 800°C, so that thermal cleaning temperature for removing native oxide came down to 800°C. As a result, the maximum process temperature of Si SEG now became 800°C, and its growth rate reached as high as 645A/min at growth temperature of 700°C.

Defect Studies in n-Type GaN Grown by Molecular Beam Epitaxy

1995 ◽  
Vol 378 ◽  
Author(s):  
W. Götz ◽  
D. B. Oberman ◽  
J. S. Harris
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Electron Cyclotron Resonance ◽  
Deep Level ◽  
Growth Parameters ◽  
Ecr Plasma ◽  
Gas Source ◽  
Deep Donor ◽  
Hall Effect Measurements ◽  
Gas Source Mbe

AbstractGaN thin films grown by molecular beam epitaxy (MBE) were characterized by Hall effect measurements in the temperature range from 80 K to 500 K and by photoluminescence spectroscopy (PL) at 2 K and at 300 K. These films were grown by MBE utilizing either electron cyclotron resonance (ECR) plasma activated nitrogen gas or thermally cracked hydrogen azide (HN3) as the source of chemically reactive nitrogen. The electrical properties of the GaN films grown by ECR plasma assisted MBE were found to vary with growth parameters, dominated either by shallow donors with activation energies (ΔE)in the range between 10 meV and 30 meV or deep donor levels (ΔE; > 500 meV). GaN grown by (HN3) gas-source MBE exhibited metallic conduction and electron mobilities <1 cm2/Vs. However, these films displayed sharp photoluminescence lines at 3.360 eV and 3.298 eV and no deep level related luminescence, whereas only broad deep level related emission was observed in the PL spectra of the ECR plasma assisted MBE grown GaN films.

Vapor Phase Epitaxy of GaN Using Gallium Tri-Chloride and Ammonia

1996 ◽  
Vol 421 ◽  
Author(s):  
M. Yuri ◽  
T. Ueda ◽  
H. Lee ◽  
K. Itoh ◽  
T. Baba ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Three Dimensional ◽  
Xrd Analysis ◽  
Vapor Phase Epitaxy ◽  
Island Growth ◽  
Gas Source ◽  
Hexagonal Polytype ◽  
Bulk Gan ◽  
Simple Growth ◽  
Gas Source Mbe

AbstractGaN films with good crystalline quality are grown on sapphire by atmospheric pressure vapor phase epitaxy using gallium tri-chloride (GaCl3) and ammonia (NH3). Epitaxial growth is carried out over temperature and V/III-ratio ranges of 800–1000°C and 100–1000, respectively. Typical growth rate obtained is in the range of 5–20 μm/hr. The films grown below 925°C typically show three dimensional (island) growth, while above that temperature, continuous films are obtained. Films grown at 975°C with a V/III ratio > 300 exhibit a smooth surface. XRD analysis shows that the films are single crystal with hexagonal polytype. Strong band-edge photoluminescence is observed with a FWHM of 60 meV at room temperature and 25 meV at 77K. The results indicate that this simple growth technique is effective for growing high quality bulk GaN, which can be used as a substrate for subsequent epitaxy. In order to further improve the surface morphology, a preliminary experiment on GaN growth on a thin GaN buffer layer prepared by gas source MBE is also presented.

Initial Stage of Heteroepitaxial Growth of SiC on Si by Gas Source MBE Using Hydrocarbon Radicals

1993 ◽  
Vol 318 ◽  
Author(s):  
Takashi Fuyuki ◽  
Yoichiro Tarui ◽  
Tomoaki Hatayama ◽  
Hiroyuki Matsunami
Keyword(s):  
Molecular Beam ◽  
High Energy ◽  
Layer Growth ◽  
Layer By Layer ◽  
Heteroepitaxial Growth ◽  
Homoepitaxial Growth ◽  
Gas Source ◽  
Initial Stage ◽  
Hydrocarbon Radicals ◽  
Gas Source Mbe

ABSTRACTHeteroepitaxial growth of 3C-SiC on Si in gas source molecular beam epitaxy ( GSMBE ) was carried out by a combination of carbonization of a Si surface and subsequent crystal growth on it using hydrocarbon radicals and Si2H6. The carbonization process and the initial stage of the subsequent growth during the intermittent supply of Si2H6 have been studied by a reflection high-energy electron diffraction (RHEED) observation. A Si surface was chemically converted to 3C-SiC at 750°C, and homoepitaxial growth on the carbonized layer could be obtained at 1000°C. Si atoms generated by thermal decomposition on a surface would react with hydrocarbon radicals, forming SiC through a layer by layer growth mode.

The Role of the In Source IN InN Growth from Molecular Beams

1998 ◽  
Vol 512 ◽  
Author(s):  
S. M. Donovan ◽  
B. Gila ◽  
J. D. MacKenzie ◽  
K. N. Lee ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Molecular Beams ◽  
Plasma Source ◽  
Nitrogen Plasma ◽  
Structural Quality ◽  
Surface Mobility ◽  
Gas Source ◽  
Oxygen Contamination ◽  
Gas Source Mbe ◽  
Carbon Concentrations

ABSTRACTInN has been grown in a gas-source MBE system using an RF nitrogen plasma source and standard TMI, solution TMI and solid In. Both solid and solution TMI produce InN with electron and carbon concentrations ≥ 1020 cm−3. Solution TMI-derived material, however, contains significantly less oxygen (8 × 1018 cm−3 vs. ≥ 1020 cm−3 for solid TMI). While the amine used to liquefy the TMI helps to displace the ether believed to be responsible for the oxygen contamination, it also appears to interfere with the growth, resulting in poorer morphology than for standard TMI. While solid In produced the lowest carrier concentration (≤ mid-1018 cm−3), it also produced the worst morphology of the sources examined, presumably due to poor surface mobility. Based on this data, it appears that carbon can play a significant role in the electrical properties of InN, and that the In source is critical in determining the structural quality.

Epitaxial growth manner and structure of superconducting oxide films

1990 ◽  
Vol 48 (4) ◽  
pp. 2-3
Author(s):  
Yoshichika Bando ◽  
Takahito Terashima ◽  
Kenji Iijima ◽  
Kazunuki Yamamoto ◽  
Kazuto Hirata ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Film Surface ◽  
High Energy ◽  
Epitaxial Films ◽  
Layer By Layer ◽  
Initial Growth ◽  
In Situ Growth ◽  
High Quality ◽  
Activated Reactive Evaporation

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.

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