Effect of growth pressure on graphene direct growth on r-plane and c-plane sapphires by low-pressure CVD

2018 ◽  
Vol 58 (SA) ◽  
pp. SAAE04 ◽  
Author(s):  
Yuki Ueda ◽  
Jumpei Yamanda ◽  
Kyosuke Fujiwara ◽  
Daichi Yamamoto ◽  
Takahiro Maruyama ◽  
...  
Keyword(s):  
Low Pressure ◽  
Growth Pressure ◽  
Direct Growth

Low Pressure Mocvd Growth of InSb

1990 ◽  
Vol 216 ◽  
Author(s):  
B.T. Cunningham ◽  
R.P. Schneider ◽  
R.M. Biefeld
Keyword(s):  
Atmospheric Pressure ◽  
Chemical Vapor ◽  
Hole Mobility ◽  
Low Pressure ◽  
Lower Growth ◽  
Growth Pressure ◽  
Mocvd Growth ◽  
Partial Pressures ◽  
Low Pressure Mocvd ◽  
Sims Analysis

ABSTRACTLow pressure (200 Torr) metalorganic chemical vapor deposition (MOCVD) of InSb has been examined through variation of the Column III (TMIn) and Column V (TMSb or TESb) precursor partial pressures. The use of lower growth pressure significantly enhanced the range of allowable Column III and Column V partial pressures in which specular morphology InSb could be obtained without the formation of In droplets or Sb crystals. In addition, a 70% improvement in the average hole mobility was obtained, compared to InSb grown in the same reactor at atmospheric pressure. SIMS analysis revealed that Si at the substrate/epitaxial layer interface is an important impurity that may contribute to degradation of the mobility. Substitution of TESb for TMSb did not result in any improvement in the purity of the InSb.

Low Pressure Homoepitaxial Growth of 4H-SiC on 4°off-Axis Substrates

2015 ◽  
Vol 821-823 ◽  
pp. 181-184 ◽  
Author(s):  
Ji Chao Hu ◽  
Yu Ming Zhang ◽  
Ren Xu Jia ◽  
Yue Hu Wang ◽  
Bin Xin
Keyword(s):  
Surface Roughness ◽  
Low Pressure ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
Growth Pressure ◽  
Step Bunching ◽  
Homoepitaxial Growth ◽  
Surface Mobility ◽  
The Impact

Step-bunching and triangular defects are significant problems in achieving higher growth rate 4H-SiC epilayers in a horizontal hot wall CVD reactor using a standard non-chlorinated chemistry of silane-propane-hydrogen on 4°off-axis substrates. In this work, the impact of growth pressure on generation of step-bunching and triangular defects and the correlations between the surface roughness and the formation of defects were investigated. It has been found that the impact of growth pressure on concentration of the triangle defects and surface roughness is obviously different. An overall reduction of defects was observed with decreasing growth pressure while the surface roughness increased. The increased adatom surface mobility in low pressure range and minimization of surface free energy are the main reasons for the phenomenon above. High Resolution X-Ray Diffraction (HRXRD) indicated that the structural quality of 4H-SiC epilayers performed at low pressure was higher than that obtained at high pressure.

Trimethylamine Alane for Low-Pressure Movpe Growth of AlGaAs-Based Materials and Device Structures

1991 ◽  
Vol 240 ◽  
Author(s):  
R. P. Schneider ◽  
R. P. Bryan ◽  
E. D. Jones ◽  
R. M. Biefeld ◽  
G. R. Olbright
Keyword(s):  
Optoelectronic Device ◽  
Low Pressure ◽  
Reaction Chamber ◽  
Cavity Surface ◽  
Growth Pressure ◽  
Wafer Thickness ◽  
Device Structures ◽  
Vertical Cavity Surface ◽  
Surface Emitting Laser ◽  
Trimethylamine Alane

ABSTRACTThe use of trimethylamine alane (TMAAl) as an alternative to trimethylaluminum (TMAl) for low-pressure metalorganic vapor-phase epitaxy (MOVPE) of AlGaAs thin films as well as complex optoelectronic device structures has been studied in detail. AlGaAs layers were grown in a horizontal reaction chamber at 20–110 mbar with growth temperatures in the range 650°C≤TG≤750°C. Wafer thickness uniformity is strongly dependent on growth pressure, and is acceptable only for the highest linear flow velocities. The 12K photoluminescence (PL) spectra of AlGaAs layers grown using TMAAl and TEGa exhibit uniformly intense and narrow bound-exciton emission throughout the growth temperature range investigated. To assess the viability of this new source for the low-pressure OMVPE growth of advanced optoelectronic devices, several optically-pumped vertical-cavity surface-emitting laser (VCSEL) structures were grown using TMAAl extensively. Room temperature lasing at 850 nm was reproducibly obtained from the VCSEL structures, with a threshold pumping power comparable to similar structures grown by molecular beam epitaxy in our laboratories.

Crystal orientation effects of sapphire substrate on graphene direct growth by metal catalyst-free low-pressure CVD

2019 ◽  
Vol 115 (1) ◽  
pp. 013103 ◽  
Author(s):  
Yuki Ueda ◽  
Jumpei Yamada ◽  
Taishi Ono ◽  
Takahiro Maruyama ◽  
Shigeya Naritsuka
Keyword(s):  
Sapphire Substrate ◽  
Crystal Orientation ◽  
Low Pressure ◽  
Metal Catalyst ◽  
Catalyst Free ◽  
Orientation Effects ◽  
Direct Growth

Direct growth of GaN on (0001) 6H–SiC by low-pressure MOVPE with a flow channel

1998 ◽  
Vol 189-190 ◽  
pp. 189-192 ◽  
Author(s):  
Makoto Kurimoto ◽  
Masao Shibata ◽  
Jun Yamamoto ◽  
Mieko Tsubamoto ◽  
Tohru Honda ◽  
...  
Keyword(s):  
Low Pressure ◽  
Flow Channel ◽  
Direct Growth

Direct Growth of GaN on (0001) Sapphire by Low Pressure Hydride Vapour Phase Epitaxy

2001 ◽  
Vol 188 (1) ◽  
pp. 439-442 ◽  
Author(s):  
E. Richter ◽  
S. Gramlich ◽  
A. Klein ◽  
E. Nebauer ◽  
I. Rechenberg ◽  
...  
Keyword(s):  
Low Pressure ◽  
Vapour Phase ◽  
Vapour Phase Epitaxy ◽  
Direct Growth

Effects of Electrical Discharges in Low Pressure Gases on the Morphology of Polyethylene Crystals

1974 ◽  
Vol 32 ◽  
pp. 544-545
Author(s):  
L.H. Bolz ◽  
D.H. Reneker
Keyword(s):  
Power Distribution ◽  
Electrical Discharge ◽  
Dielectric Breakdown ◽  
Ionic Species ◽  
Low Pressure ◽  
Polymer Surfaces ◽  
Electrical Discharges ◽  
Adhesive Bonds ◽  
Power Distribution Lines ◽  
Modification Of The Surface

The attack, on the surface of a polymer, by the atomic, molecular and ionic species that are created in a low pressure electrical discharge in a gas is interesting because: 1) significant interior morphological features may be revealed, 2) dielectric breakdown of polymeric insulation on high voltage power distribution lines involves the attack on the polymer of such species created in a corona discharge, 3) adhesive bonds formed between polymer surfaces subjected to such SDecies are much stronger than bonds between untreated surfaces, 4) the chemical modification of the surface creates a reactive surface to which a thin layer of another polymer may be bonded by glow discharge polymerization.

Field ion microscopy

1988 ◽  
Vol 46 ◽  
pp. 434-435
Author(s):  
Gert Ehrlich
Keyword(s):  
Low Temperature ◽  
Sample Surface ◽  
Low Pressure ◽  
Radius Of Curvature ◽  
Field Ion Microscopy ◽  
Phosphor Screen ◽  
Ion Microscopy ◽  
Field Ion Microscope

The field ion microscope, devised by Erwin Muller in the 1950's, was the first instrument to depict the structure of surfaces in atomic detail. An FIM image of a (111) plane of tungsten (Fig.l) is typical of what can be done by this microscope: for this small plane, every atom, at a separation of 4.48Å from its neighbors in the plane, is revealed. The image of the plane is highly enlarged, as it is projected on a phosphor screen with a radius of curvature more than a million times that of the sample. Müller achieved the resolution necessary to reveal individual atoms by imaging with ions, accommodated to the object at a low temperature. The ions are created at the sample surface by ionization of an inert image gas (usually helium), present at a low pressure (< 1 mTorr). at fields on the order of 4V/Å.

Sign in / Sign up

Export Citation Format

Share Document