scholarly journals Morphology and surface reconstructions of m-plane GaN

2002 ◽  
Vol 743 ◽  
Author(s):  
C. D. Lee ◽  
R. M. Feenstra ◽  
J. E. Northrup ◽  
L. Lymperakis ◽  
J. Neugebauer

ABSTRACTM-plane GaN(1100) is grown by plasma assisted molecular beam epitaxy on ZnO(1100) substrates. A low-temperature GaN buffer layer is found to be necessary to obtain good structural quality of the films. Well oriented (1100) GaN films are obtained, with a slate like surface morphology. On the GaN(1100) surfaces, reconstructions with symmetry of c(2×2) and approximate “4×5” are found under N- and Ga-rich conditions, respectively. We propose a model for Ga-rich conditions with the “4×5” structure consisting of ≥ 2 monolayers of Ga terminating the GaN surface.

2020 ◽  
Vol 116 (19) ◽  
pp. 192105 ◽  
Author(s):  
S. Inagaki ◽  
M. Nakamura ◽  
N. Aizawa ◽  
L. C. Peng ◽  
X. Z. Yu ◽  
...  

CrystEngComm ◽  
2014 ◽  
Vol 16 (46) ◽  
pp. 10721-10727 ◽  
Author(s):  
Fangliang Gao ◽  
Lei Wen ◽  
Yunfang Guan ◽  
Jingling Li ◽  
Xiaona Zhang ◽  
...  

The as-grown In0.53Ga0.47As epi-layer grown on Si substrate by using low-temperature In0.4Ga0.6As buffer layer with in-situ annealing is of a high degree of structural perfection.


1990 ◽  
Vol 198 ◽  
Author(s):  
Zuzanna Liliental-Weber

ABSTRACTThe structural quality of GaAs layers grown at 200°C by molecular beam epitaxy (MBE) was investigated by transmission electron microscopy (TEM). We found that a high crystalline perfection can be achieved in the layers grown at this low temperature for thickness up to 3 μm. In some samples we observed pyramid-shaped defects with polycrystalline cores surrounded by microtwins, stacking faults and dislocations. The size of these cores increased as the growth temperature was decreased and as the layer thickness was increased. The upper surface of layers with pyramidal defects became polycrystalline at a critical thickness of the order of 3μm. We suggested that the low-temperature GaAs becomes polycrystalline at a critical thickness either because of a decrease in substrate temperature during growth or because strain induced by excess As incorporated in these layers leads to the formation of misoriented GaAs nuclei, thereby initiating polycrystalline growth. The pyramidal shape of the defects results from a growth-rate hierarchy of the low index planes in GaAs.


1991 ◽  
Vol 256 ◽  
Author(s):  
H. Presting ◽  
U. Menczigar ◽  
G. Abstreiter ◽  
H. Kibbel ◽  
E. Kasper

ABSTRACTP-i-n doped short-period SimGen strained layer superlattices (SLS) are grown on (100) silicon substrates by low temperature molecular beam epitaxy (300C°<∼Tg<∼400C°). The SLS's are grown with period lengths around 10 monolayers (ML) to a thickness of 250nm on a rather thin (50nm) homogeneous Si1−ybGeyb alloy buffer layer serving as strain symmetrizing substrate. Photoluminescence at T=5K is observed for various SimGen SLS samples, the strongest signal was found for a Si5 Ge5 SLS. Samples with identical SLS's but different buffer layer composition and thicknesses are grown to study the influence of strain on the PL. Electroluminescence (EL) at the same energy range is observed from mounted SimGen SLS mesa and waveguide diodes up to T=130K – for the first time reported in strain symmetrized short-period SimGen SLS. The intensity and peak positon of the EL signal was found to be dependent on the injected electrical power.


1989 ◽  
Vol 7 (2) ◽  
pp. 517-522 ◽  
Author(s):  
R. J. Koestner ◽  
H.‐Y. Liu ◽  
H. F. Schaake ◽  
T. R. Hanlon

Author(s):  
B. Riah ◽  
Julien Camus ◽  
Abdelhak Ayad ◽  
Mohammad Rammal ◽  
Raouia Zernadji ◽  
...  

This paper reports the effect of silicon substrate orientation and aluminum nitride buffer layer deposited by molecular beam epitaxy on the growth of aluminum nitride thin films deposited by DC magnetron sputtering technique at low temperature. The structural analysis has revealed a strong (0001) fiber texture for both substrates Si (100) and (111) and a hetero-epitaxial growth on few nanometers AlN buffer layer grown by MBE on Si (111) substrate. SEM images and XRD characterization have shown an enhancement in AlN crystallinity thanks to AlN (MBE) buffer layer. Raman spectroscopy indicated that the AlN film was relaxed when it deposited on Si (111), in compression on Si (100) and under tension on AlN buffer layer grown by MBE/Si (111) substrates, respectively. The interface between Si (111) and AlN grown by MBE is abrupt and well defined; contrary to the interface between AlN deposited using PVD and AlN grown by MBE. Nevertheless, AlN hetero-epitaxial growth was obtained at low temperature (&lt;250&deg;C).


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