Effect of ammonia pretreatment on crystal quality of N-polar GaN grown on SiC by metalorganic chemical vapor deposition

2019 ◽  
Vol 675 ◽  
pp. 148-152
Author(s):  
Uiho Choi ◽  
Kyeongjae Lee ◽  
Jaeyeon Han ◽  
Taehoon Jang ◽  
Yongjun Nam ◽  
...  
1999 ◽  
Vol 14 (3) ◽  
pp. 1132-1136 ◽  
Author(s):  
Anchuan Wang ◽  
John A. Belot ◽  
Tobin J. Marks

High-quality epitaxial or highly textured NiO thin films can be grown at temperatures of 400–750°C by low-pressure metalorganic chemical vapor deposition (MOCVD) on MgO, SrTiO3, C-cut sapphire, as well as on single crystal and highly textured Ni (200) metal substrates using Ni(dpm)2 (dpm – dipivaloylmethanate) as the volatile precursor and O2 or H2O as the oxidizer/protonolyzer. X-ray diffraction (XRD), scanning electron microscopy/energy dispersive detection (SEM/EDX), and atomic force microscopy (AFM) confirm that the O2-derived NiO films are smooth and that the quality of the epitaxy can be improved by decreasing the growth temperature and/or the precursor flow rate. However, low growth temperatures (400–500 °C) lead to rougher surfaces and carbon contamination. The H2O-derived NiO films, which can be obtained only at relatively high temperatures (650–750 °C), exhibit slightly broader ω scan full width half-maximum (FWHM) values and rougher surfaces but no carbon contamination. Using H2O as the oxidizer/protonolyzer, smooth and highly textured NiO (111) films can be grown on easily oxidized single crystal and highly textured Ni (200) metal substrates, which is impossible when O2 is the oxidizer. The textural quality of these films depends on both the quality of the metal substrates and the gaseous precursor flow rate.


1992 ◽  
Vol 7 (8) ◽  
pp. 2186-2193 ◽  
Author(s):  
B. Molnar ◽  
P. Chi ◽  
D. Simons

A study of the cross doping of GaAs layers grown by a two-step metalorganic chemical vapor deposition on Si substrates is reported. All as-grown, unintentionally doped layers of GaAs were n-type, and the carrier profiles tracked the Si atomic profiles. Furnace annealing at 850 °C for 30 min in an arsine overpressure, which is used to improve the crystalline quality of the GaAs near the heterointerface, caused additional Si to diffuse into the GaAs layer. Comparison of the Si concentration at the interface with the carrier concentration suggested the presence of compensating acceptors. Resonance Raman scattering by the SiAs local vibrational mode near the interface shows that a fraction of the Si atoms are localized at the As sites. The furnace annealing increased the Si concentration in the 1.7–1.8 μm thick initially grown GaAs layer. This, in turn, influenced the electrical profiles created with Si or Be implantation on a 2.3 μm thick GaAs layer.


1990 ◽  
Vol 208 ◽  
Author(s):  
T. J. Kistenmacher ◽  
W. A. Bryden ◽  
D. K. Wickenden ◽  
S. A. Ecelberger

ABSTRACTThe X-ray precession method has been utilized to study texture and heteroepitaxy for thin films of the Group IIIA nitrides deposited on a variety of amorphous and single-crystal substrates. Films of InN were synthesized by reactive rfmagnetron sputtering [employing an elemental target and N2 as the sputtering gas], while the GaN films were deposited by metalorganic chemical vapor deposition [utilizing (CH 3 ) 3Ga and NH3 as sources]. The quality of (00.1) textured films of InN on fused quartz and slightly off-axis (111) Si are taken as initial examples of the versatility of the X-ray precession method. The powder rings evolving from a lack of azimuthal coherence for InN films grown on quartz are contrasted with the scattering from weakly correlated (pseudo heteroepitaxial) domains for films grown on (111) Si. These latter scattering features are then compared with those from the true heteroepitaxial deposition of InN onto the (111) face of cubic ZrO2. And, finally, the scattering from the heteroepitaxial growth of InN and GaN on the (00.1) face of sapphire and some initial studies on the effect of nucleation layers on twinning in the GaN films are presented.


Sign in / Sign up

Export Citation Format

Share Document