Low defect-mediated reverse-bias leakage in (0001) GaN via high-temperature molecular beam epitaxy

2010 ◽  
Vol 96 (10) ◽  
pp. 102111 ◽  
Author(s):  
J. J. M. Law ◽  
E. T. Yu ◽  
G. Koblmüller ◽  
F. Wu ◽  
J. S. Speck
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.


1998 ◽  
Vol 537 ◽  
Author(s):  
C.T. Foxon ◽  
T.S. Cheng ◽  
D. Korakakis ◽  
S.V. Novikov ◽  
R.P. Campion ◽  
...  

AbstractVarious methods have been used to initiate growth by Molecular Beam Epitaxy (MBE) of GaN on sapphire, or other substrates, but there is always a problem with morphology and with a high defect density which results in the formation of a sub-grain boundary structure. We show that by using, homo-epitaxial growth on properly prepared bulk GaN substrates, combined with high temperature growth, we obtain a significant improvement in surface morphology. Growth at sufficiently high temperature leads to a rapid smoothing of the surface and to almost atomically flat surfaces over relatively large areas. Multi-Quantum Well structures grown on such GaN epitaxial films are dislocation free with abrupt interfaces.


1999 ◽  
Vol 572 ◽  
Author(s):  
C. M. Lueng ◽  
H. L. W. Chan ◽  
W. K. Fong ◽  
C. Surya ◽  
C. L. Choy

ABSTRACTAluminum nitride (AlN) and gallium nitride (GaN) thin films have potential uses in high temperature, high frequency (e.g. microwave) acoustic devices. In this work, the piezoelectric coefficients of wurtzite AlN and GaN/AlN composite film grown on silicon substrates by molecular beam epitaxy were measured by a Mach-Zehnder type heterodyne interferometer. The effects of the substrate on the measured coefficients are discussed.


Author(s):  
T. S. Cheng ◽  
A. Summerfield ◽  
C. J. Mellor ◽  
G. Cassabois ◽  
B. Gil ◽  
...  

1984 ◽  
Vol 35 ◽  
Author(s):  
Loren Pfeiffer ◽  
Julia M. Phillips ◽  
T.P. Smith ◽  
W. M. Augustyniak ◽  
K. W. West

ABSTRACTWe show that post anneals of short duration at high temperature can markedly improve the quality of CaF2 films grown by molecular beam epitaxy (MBE) on Si (100). Anneals at 1100°C for 20 sec in an Ar ambient improved χmin, the ratio of backscattered 1.8 MeV He4 ions in the aligned to random direction, from as-grown values of .07 to .26, to post post-anneal values of .03 to .045. This is the best χmin yet reported for the CaF2:Si system. The post-annealed films also show improved resistance to chemical etching and mechanical stress, and increased dielectric breakdown voltages.


2005 ◽  
Vol 286 ◽  
pp. 150-153
Author(s):  
J.J. Lee ◽  
M.Y. Kim ◽  
J.H. Song ◽  
Y. Cui ◽  
A.J. Freeman ◽  
...  

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yong-Jin Cho ◽  
Alex Summerfield ◽  
Andrew Davies ◽  
Tin S. Cheng ◽  
Emily F. Smith ◽  
...  

Abstract We demonstrate direct epitaxial growth of high-quality hexagonal boron nitride (hBN) layers on graphite using high-temperature plasma-assisted molecular beam epitaxy. Atomic force microscopy reveals mono- and few-layer island growth, while conducting atomic force microscopy shows that the grown hBN has a resistance which increases exponentially with the number of layers, and has electrical properties comparable to exfoliated hBN. X-ray photoelectron spectroscopy, Raman microscopy and spectroscopic ellipsometry measurements on hBN confirm the formation of sp2-bonded hBN and a band gap of 5.9 ± 0.1 eV with no chemical intermixing with graphite. We also observe hexagonal moiré patterns with a period of 15 nm, consistent with the alignment of the hBN lattice and the graphite substrate.


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