IR-VUV Dielectric Function of Al1−xInxN determined by Spectroscopic Ellipsometry

2000 ◽  
Vol 639 ◽  
Author(s):  
A. Kasic ◽  
M. Schubert ◽  
B. Rheinländer ◽  
J. Off ◽  
F. Scholz ◽  
...  
Keyword(s):  
Dielectric Function ◽  
Spectral Range ◽  
Spectroscopic Ellipsometry ◽  
Vacuum Ultraviolet ◽  
Phonon Mode ◽  
Film Growth ◽  
Mode Frequency ◽  
Buffer Layers ◽  
Mid Infrared ◽  
Theoretical Predictions

ABSTRACTSpectroscopic Ellipsometry from the mid-infrared (mid-ir) to the vacuum-ultraviolet (vuv) spectral range (350 cm−1 … 8.8 eV) is used to study the optical properties of hexagonal MOVPE-grown Al1−xInxN films for 0.11 ≤ × ≤ 0.21. The AlInN E1(TO) phonon shows a onemode behavior in contrast to recent theoretical predictions [H. Grille, Ch. Schnittler, and F. Bechstedt, Phys. Rev. B 61, 6091 (2000)]. Approximately 120 nm thick Al1−xInxN films grown on slightly compressively strained hexagonal GaN buffer layers reveal the influence of in-plane strain on the E1(TO) phonon mode frequencies. Al1−xInxN deposited directly on [0001] sapphire substrate possesses E1(TO) mode frequency which indicate fully relaxed film growth. For highquality Al0.890In0.110N one A1(LO) phonon mode was observed. Furthermore, we present the complex dielectric function of hexagonal Al0.872In0.128N from the mid-ir to vuv spectral range.

Determination and Critical Assessment of the Optical Properties of Common Substrate Materials Used in III-V Nitride Heterostructures with Vacuum Ultraviolet Spectroscopic Ellipsometry

2001 ◽  
Vol 693 ◽  
Author(s):  
N.V. Edwards ◽  
O.P.A. Lindquist ◽  
L.D. Madsen ◽  
S. Zollner ◽  
K. Järrehdahl ◽  
...  
Keyword(s):  
Optical Properties ◽  
Dielectric Function ◽  
Spectroscopic Ellipsometry ◽  
Optical Constants ◽  
Vacuum Ultraviolet ◽  
Critical Assessment ◽  
Optical Transitions ◽  
Common Substrate ◽  
Materials Used

AbstractAs a first step toward enabling the in-line metrology of III-V nitride heterostructure and materials, we present the optical constants of the two common substrate materials over an unprecendented spectral range. Vacuum Ultraviolet spectroscopic ellipsometry (VUVSE) was used to obtain the optical constants for Al2O3 and the ordinary and extra-ordinary component of the dielectric function for both 4H- and 6H-SiC. The results are discussed in the context of anisotropy, polytypism, bandstructure, optical transitions, and preparation/characterization of abrupt surfaces, where appropriate.

The Study of Damage Profile of Ion Implanted Layer on Si by Spectroscopic Ellipsometry

1982 ◽  
Vol 14 ◽  
Author(s):  
Jinshen Luo ◽  
P.J. Mc Marr ◽  
K. Vedam
Keyword(s):  
Dielectric Function ◽  
Spectral Range ◽  
Spectroscopic Ellipsometry ◽  
Ion Implanted

ABSTRACTWe have determined the dielectric function of silicon samples which were implanted with 100-150 KeV P, As, Si ions to doses of 2·1014-1·1016cm−2, by a rotating analyser Automated ellipsometer in the spectral range 1.77− 4.59 eV. These data have been analyzed using a simplified three layer model.The results are compared with an earlier ellipsometric investigation [2].

Parametric modeling of the dielectric function and identification of the critical point of a CdMgTe alloy in the vacuum ultraviolet spectral range

2012 ◽  
Vol 60 (8) ◽  
pp. 1219-1223
Author(s):  
Tae Jung Kim ◽  
Tae Ho Ghong ◽  
Jae Jin Yoon ◽  
Soon Yong Hwang ◽  
Nilesh Barange ◽  
...  
Keyword(s):  
Critical Point ◽  
Dielectric Function ◽  
Spectral Range ◽  
Vacuum Ultraviolet ◽  
Parametric Modeling

Dielectric function of hexagonal AlN films determined by spectroscopic ellipsometry in the vacuum-uv spectral range

1999 ◽  
Vol 59 (3) ◽  
pp. 1845-1849 ◽  
Author(s):  
T. Wethkamp ◽  
K. Wilmers ◽  
C. Cobet ◽  
N. Esser ◽  
W. Richter ◽  
...  
Keyword(s):  
Dielectric Function ◽  
Spectral Range ◽  
Spectroscopic Ellipsometry ◽  
Vacuum Uv

Dielectric function of cubic InN from the mid-infrared to the visible spectral range

2008 ◽  
Vol 23 (5) ◽  
pp. 055001 ◽  
Author(s):  
P Schley ◽  
R Goldhahn ◽  
C Napierala ◽  
G Gobsch ◽  
J Schörmann ◽  
...  
Keyword(s):  
Dielectric Function ◽  
Spectral Range ◽  
Visible Spectral Range ◽  
Mid Infrared

From Semiconductor to Metal in a Flash: Observing Ultrafast Laser-Induced Phase Transformations

1997 ◽  
Vol 481 ◽  
Author(s):  
J. P. Callan ◽  
A. M.-T. Kim ◽  
L. Huangt ◽  
E. N. Glezer ◽  
E. Mazur
Keyword(s):  
Phase Transformations ◽  
Dielectric Function ◽  
Spectral Range ◽  
Laser Excitation ◽  
Spectroscopic Technique ◽  
Ultrafast Laser ◽  
Lattice Heating ◽  
Fs Laser

ABSTRACTWe use a new broadband spectroscopic technique to measure ultrafast changes in the dielectric function of a material over the spectral range 1.5–3.5 eV following intense 70-fs laser excitation. The results reveal the nature of the phase transformations which occur in the material following excitation. We studied the response of GaAs and Si. For GaAs, there are three distinct regimes of behavior as the pump fluence is increased — lattice heating, lattice disordering, and a semiconductor-to-metal transition.

Composition and Structure of Epitaxial CaF2 Layers at the First Stages of Their Growth on Si(111)

2001 ◽  
Vol 696 ◽  
Author(s):  
R. Würz ◽  
W. Bohne ◽  
W. Fuhs ◽  
J. Röhrich ◽  
M. Schmidt ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Stoichiometric Composition ◽  
Interface Reaction ◽  
Heavy Ion ◽  
Interface Layer ◽  
Buffer Layers ◽  
Ex Situ ◽  
Elastic Recoil ◽  
Detection Analysis

AbstractCaF2 films with thicknesses in the monolayer range (<20 Å) were grown on Si(111) by evaporation from a CaF2 source at UHV conditions. They were characterized ex-situ by Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA), RBS/Channeling, X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). The F/Ca ratio of the films was found to depend on the growth temperature Ts and to deviate appreciably from the stoichiometric composition (F/Ca=2). Due to an interface reaction which leads to a CaF-interface layer a change from polycrystalline to epitaxial growth occurs at Ts=450°C. At higher temperature film growth started with a closed layer of CaF on top of which CaF2 layers with an increasing fraction of pinholes were formed. By means of a two-step process at different temperatures, the amount of pinholes could be strongly reduced. It was found, that buffer layers of CaF2 with a CaF interface layer introduced in Au/p-Si contacts enhance the barrier height by as much as 0.36eV to values of 0.64eV.

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