Epitaxial Growth of CoGa on (100)GaAs by Metal-Organic Molecular Beam Epitaxy

1998 ◽  
Vol 514 ◽  
Author(s):  
N. Viguier ◽  
F. Maury

ABSTRACTEpitaxial layers of the intermetallic β-CoGa cubic phase were grown at low temperature on (100)GaAs by metal-organic molecular beam epitaxy (MOMBE) using GaEt3 and CpCo(CO)2 as vapor sources. The film composition and the lattice mismatch on (100)GaAs may be adjusted by controlling the molecular beam pressure ratio. The growth on a Co-saturated GaAs surface leads to the formation of bi-phased CoGa-CoAs films whereas epitaxial single-phased β-CoGa layers are grown on a Ga-terminated GaAs surface with the simple cube on cube orientation [100](001 )CoGa//[100](001)GaAs. Annealing experiments under inert atmosphere have shown that MOMBE CoGa films are thermally stable on GaAs until ca. 823 K. Ohmic and Schottky CoGa/GaAs contacts have been made depending on the doping of the substrate by this process.

1998 ◽  
Vol 535 ◽  
Author(s):  
A. Hierro ◽  
D. Kwon ◽  
S. A. Ringel ◽  
L. J. Brillson ◽  
A. P. Young ◽  
...  

AbstractDeep level defects have been detected and analyzed in epitaxial ZnSe layers grown by molecular beam epitaxy (MBE) on GaAs and on In0.04Ga0.96As using deep level optical spectroscopy (DLOS). A series of samples, which differ only in the initial Zn:Se beam pressure ratio (BPR = 1:1, 1:10, 10:1) during the growth nucleation step, were characterized by DLOS in order to assess the dependence of bulk deep level formation on interface nucleation conditions. The transient and steady state photocapacitance measurements were performed using 100 W Quartz Halogen and 450 W Xe lamps as light sources, in the spectral range of 0.9 to 2.9 eV with a resolution better than 0.02 eV. The capacitance transients were recorded for time windows of 10 msec to 5 sec after light excitation of the sample, which was kept at a temperature of 100 K. Using semi-transparent Au Schottky contacts, several deep levels in the ZnSe layer were detected for all BPR's, with optical threshold energies of 1.1, 1.46 and 1.9 eV below the conduction band. These energies were obtained from the slope of the capacitance transient at different time intervals and were confirmed by steady state photocapacitance. The concentration of the levels was in the range 1012 to 1014 cm−3. Both the 1.1 and 1.46 eV trap concentrations were found to depend strongly on lattice mismatch conditions, whereas the latter was shown to largely depend on BPR. The optical threshold of the 1.9 eV trap correlates well with a ˜1.9 eV cathodoluminescence (CL) peak, which has been previously associated with either Zn vacancies or Gazn substitutional defects in Zn-deficient material.


2021 ◽  
Vol 549 ◽  
pp. 149245
Author(s):  
Chaomin Zhang ◽  
Kirstin Alberi ◽  
Christiana Honsberg ◽  
Kwangwook Park

2001 ◽  
Vol 696 ◽  
Author(s):  
Gu Hyun Kim ◽  
Jung Bum Choi ◽  
Joo In Lee ◽  
Se-Kyung Kang ◽  
Seung Il Ban ◽  
...  

AbstractWe have studied infrared photoluminescence (PL) and x-ray diffraction (XRD) of 400 nm and 1500 nm thick InAs epilayers on GaAs, and 4 nm thick InAs on graded InGaAs layer with total thickness of 300 nm grown by molecular beam epitaxy. The PL peak positions of 400 nm, 1500 nm and 4 nm InAs epilayer measured at 10 K are blue-shifted from that of InAs bulk by 6.5, 4.5, and 6 meV, respectively, which can be largely explained by the residual strain in the epilayer. The residual strain caused by the lattice mismatch between InAs and GaAs or graded InGaAs/GaAs was observed from XRD measurements. While the PL peak position of 400 nm thick InAs layer is linearly shifted toward higher energy with increase in excitation intensity ranging from 10 to 140 mW, those of 4 nm InAs epilayer on InGaAs and 1500 nm InAs layer on GaAs is gradually blue-shifted and then, saturated above a power of 75 mW. These results suggest that adopting a graded InGaAs layer between InAs and GaAs can efficiently reduce the strain due to lattice mismatch in the structure of InAs/GaAs.


2012 ◽  
Vol 5 (4) ◽  
pp. 045501 ◽  
Author(s):  
Chia-Hung Lin ◽  
Shota Uchiyama ◽  
Takahiro Maruyama ◽  
Shigeya Naritsuka

1989 ◽  
Vol 160 ◽  
Author(s):  
Y.H. Lee ◽  
R.P. Burns ◽  
J.B. Posthill ◽  
K.J. Bachmann

AbstractThe growth of Mo overtayers and Mo-Ni multilayers on single crystal Ni(001) substrates is described. The nucleation and growth processes of these thin films were analyzed by LEED, XPS, AES and SEM and High Resolution AES investigations without breaking vacuum. Growth of Mo-Ni multilayer heterostructures on Ni(001) with ≈20Å periodicity is possible at low temperature (≈200 °C). At high temperature (≈550 °C) the growth proceeds by the Volmer-Weber mechanism preventing the deposition of small period multilayers. Annealing experiments on ultra-thin (<20Å) Mo overiayers deposited at 200 °C show an onset of interdiffusion at ≈ 550°C coupled to the generation of a new surface periodicity.


2000 ◽  
Vol 639 ◽  
Author(s):  
Ryuhei Kimura ◽  
Kiyoshi Takahashi ◽  
H. T. Grahn

ABSTRACTAn investigation of the growth mechanism for RF-plasma assisted molecular beam epitaxy of cubic GaN films using a nitrided AlGaAs buffer layer was carried out by in-situ reflection high energy electron diffraction (RHEED) and high resolution X-ray diffraction (HRXRD). It was found that hexagonal GaN nuclei grow on (1, 1, 1) facets during nitridation of the AlGaAs buffer layer, but a highly pure, cubic-phase GaN epilayer was grown on the nitrided AlGaAs buffer layer.


1987 ◽  
Vol 50 (1) ◽  
pp. 37-39 ◽  
Author(s):  
K. Mohammed ◽  
D. A. Cammack ◽  
R. Dalby ◽  
P. Newbury ◽  
B. L. Greenberg ◽  
...  

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