Anisotropic dielectric response and surface aging of mercuric iodide crystal studied by variable angle spectroscopic ellipsometry

1998 ◽  
Vol 313-314 ◽  
pp. 351-355 ◽  
Author(s):  
H. Yao ◽  
Jay C. Erickson ◽  
L.A. Lim ◽  
Ralph B. James
Keyword(s):  
Spectroscopic Ellipsometry ◽  
Dielectric Response ◽  
Mercuric Iodide ◽  
Anisotropic Dielectric ◽  
Variable Angle ◽  
Variable Angle Spectroscopic Ellipsometry ◽  
Iodide Crystal

Variable Angle Spectroscopic Ellipsometry Studies of HgI2

1993 ◽  
Vol 302 ◽  
Author(s):  
Huade Yao ◽  
Blaine Johs
Keyword(s):  
Optical Properties ◽  
Spectroscopic Ellipsometry ◽  
Room Temperature ◽  
Field Vector ◽  
Electric Field Vector ◽  
Aging Effects ◽  
Anisotropic Dielectric ◽  
Variable Angle ◽  
Variable Angle Spectroscopic Ellipsometry ◽  
Oriented Parallel

ABSTRACTVariable angle spectroscopic ellipsometry (VASE) measurements were employed to study the optical properties of HgI2. The bulk crystal HgI2 surface was subjected to a 10% KI etching prior to the VASE measurements. SE measurements were performed at room temperature, in air with several different angles of incidence. The uniaxial anisotropic nature of the HgI2 crystal was treated in the VASE analysis. Anisotropic dielectric functions of single crystal HgI2, ε||(wo) and ε⊥(ω), for optical electric field vector oriented parallel and perpendicular to the c axis, respectively, were obtained in the range of ∼2.0 - 5.0 eV. Surface aging effects of the HgI2 crystal, after the 10% KI etching, were characterized by VASE.

Optical Dielectric Response of Gallium Nitride Studied by Variable Angle Spectroscopic Ellipsometry

1996 ◽  
Vol 449 ◽  
Author(s):  
H. Yao ◽  
C. H. Yan ◽  
H. A. Jenkinson ◽  
J. M. Zavada ◽  
J. S. Speck ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Band Gap ◽  
Spectroscopic Ellipsometry ◽  
Dielectric Response ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Angle Of Incidence ◽  
Light Emitting ◽  
Variable Angle ◽  
Variable Angle Spectroscopic Ellipsometry

ABSTRACTVariable angle spectroscopic ellipsometry (VASE) and transmission measurements have been employed to study the dielectric response of gallium nitride (GaN) thin films — an important material for light emitting diodes (LEDs) and laser diodes applications. The GaN films were grown by atomsphere pressure metal organic chemical vapor deposition (MOCVD) on c-plane sapphire substrates (α-AI2O3). Room temperature VASE measurements were made, in the range of 0.75 to 5.5eV, at the angle of incidence of 73, 75, and 77 degree, respectively. Evidence of anisotropy is observed especially in the spectral range under the band gap (∼3.4 eV), reflecting the nature of wurtzite crystal structure of GaN. The ordinary dielectric function ε⊥(ω) of GaN were obtained through the analysis of transmission and VASE data in the range below and above the band gap. The thickness of these GaN films is also determined via the analysis.

scholarly journals Thin‐film hermeticity: A quantitative analysis of diamondlike carbon using variable angle spectroscopic ellipsometry

1988 ◽  
Vol 64 (8) ◽  
pp. 4175-4180 ◽  
Author(s):  
S. Orzeszko ◽  
Bhola N. De ◽  
John A. Woollam ◽  
John J. Pouch ◽  
Samuel A. Alterovitz ◽  
...  
Keyword(s):  
Thin Film ◽  
Quantitative Analysis ◽  
Spectroscopic Ellipsometry ◽  
Variable Angle ◽  
Diamondlike Carbon ◽  
Variable Angle Spectroscopic Ellipsometry

In-line Characterization of Thin Polysilicon Films by Variable Angle Spectroscopic Ellipsometry

2000 ◽  
Vol 609 ◽  
Author(s):  
S. Paprotta ◽  
K. S. Röver ◽  
R. Ferretti ◽  
U. Höhne ◽  
J. D. Kähler ◽  
...  
Keyword(s):  
Spectroscopic Ellipsometry ◽  
Complex Refractive Index ◽  
Deposition Process ◽  
Oxide Thickness ◽  
Interface Layer ◽  
Parameter Determination ◽  
Variable Angle ◽  
Air Interface ◽  
Polysilicon Films ◽  
Variable Angle Spectroscopic Ellipsometry

ABSTRACTUp to now an in-line method for parameter determination of deposited thin polysilicon films is not available. In this paper a method for monitoring the polysilicon deposition process in device manufacturing by variable angle spectroscopic ellipsometry (VASE) is demonstrated. Therefore several polysilicon films are deposited on thermally oxidized [100] silicon wafers. These samples are characterized by VASE in the optical range of 450 - 850 nm. Parameters are determined by simulation using a multilayer model consisting of air, interface layer (surface roughness), polysilicon, SiO2 and silicon substrate. Different optical models representing the properties of polysilicon are tested. The free parameters are the oxide thickness, the composition and the thickness of the interface layer (air, polysilicon) as well as the thickness and the complex refractive index of the polysilicon layer. Results of the spectroscopic analysis are verified by AFM and SEM measurements. It can be shown that parameters of the deposited polysilicon films, which often could only be determined by complex and destructive off-line analysis methods are also accessible by non-destructive in-line VASE measurements.

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