Optical Characterization and Modeling of Amorphous Hydrogenated Carbon Films

1994 ◽  
Vol 349 ◽  
Author(s):  
William A. McGahan ◽  
John A. Woollam
Keyword(s):  
Optical Constants ◽  
Optical Characterization ◽  
Industrial Applications ◽  
Carbon Films ◽  
Plasma Cvd ◽  
Complete Structure ◽  
Glass Substrates ◽  
General Energy ◽  
Transmission Measurements ◽  
Amorphous Hydrogenated Carbon

ABSTRACTAmorphous hydrogenated carbon (a-C:H) thin films are of great importance in a number of industrial applications due to their hardness, chemical stability, and optical transparency. In many applications, the thickness of the a-C:H film and/or its optical properties are critical for the performance of the complete structure, and, as a result, a means of measuring these quantities is important. In this work we review the use of spectroscopic ellipsometry and transmission measurements for the estimation of the thickness and optical constants of thin a-C:H films. Spectra are shown for films exhibiting Tauc effective bandgaps ranging from 0 - 2.3 eV. The films were prepared by magnetron sputtering and plasma CVD on both silicon and glass substrates. The general energy dependence of the a-C:H optical constants is discussed in terms of the absorption processes which occur in the film.

Deposition of amorphous hydrogenated carbon films on Si and PMMA by pulsed direct-current plasma CVD

2011 ◽  
Vol 519 (20) ◽  
pp. 6688-6692 ◽  
Author(s):  
Ta-Lun Sung ◽  
Yu-An Chao ◽  
Chung-Ming Liu ◽  
Kungen Teii ◽  
Shinriki Teii ◽  
...  
Keyword(s):  
Direct Current ◽  
Carbon Films ◽  
Plasma Cvd ◽  
Direct Current Plasma ◽  
Pulsed Direct Current ◽  
Amorphous Hydrogenated Carbon

Photoconductivity of amorphous hydrogenated carbon films prepared by plasma CVD of acetylene

Vacuum ◽  
1996 ◽  
Vol 47 (9) ◽  
pp. 1047-1051 ◽  
Author(s):  
M Basu ◽  
AB Maity ◽  
B Maiti ◽  
S Chaudhuri ◽  
AK Pal
Keyword(s):  
Carbon Films ◽  
Plasma Cvd ◽  
Amorphous Hydrogenated Carbon

Characterization Of Amorphous Carbon Films Based On Carbon, Nitrogen, and hydrogen*.

1995 ◽  
Vol 415 ◽  
Author(s):  
H. Efstathiadis ◽  
Z. Akkerman ◽  
F. W. Smith
Keyword(s):  
Optical Constants ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Amorphous Carbon Films ◽  
A Value ◽  
Energy Gaps ◽  
Free Energy Model ◽  
Nitrogen Alloy ◽  
Amorphous Hydrogenated Carbon

ABSTRACTA series of amorphous hydrogenated carbon-nitrogen alloy films (a-CxNyHz) has been prepared via plasma-enhanced chemical vapor deposition from mixtures of nitrogen and acetylene. It is found that as the ratio R=N2/C2H2 is increased from zero to 100, the nitrogen incorporation into the films is increasing while the deposition rate is decreasing for 0<R<10 and is saturating at a value of about 1.0 A/sec for 10<R<100. The absorption associated with the N-H stretching mode increases while that of the C-H stretching mode decreases with increase of R. The optical constants and the energy gaps of these films have also been determined. A free energy model previously developed for the prediction of the bonding in amorphous a-CxHyalloys is extended and applied here to a-CxNyHz. Predictions are presented for the bonding of tetrahedral C(sp3), trigonal C(sp2), linear C(sp1), pyramidal N(sp 3), trigonal N(sp 2), and linear N(sp1) atoms in the alloy, and the bonding of H to these atoms.

An Study of Influence of Imperfections on the Delamination of Diamond-Like Carbon Films

2002 ◽  
Vol 719 ◽  
Author(s):  
Myoung-Woon Moon ◽  
Kyang-Ryel Lee ◽  
Jin-Won Chung ◽  
Kyu Hwan Oh
Keyword(s):  
Cross Sections ◽  
Focused Ion Beam ◽  
Imaging System ◽  
Ion Beam ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Glass Substrates ◽  
Atomic Force ◽  
Initiation And Propagation

AbstractThe role of imperfections on the initiation and propagation of interface delaminations in compressed thin films has been analyzed using experiments with diamond-like carbon (DLC) films deposited onto glass substrates. The surface topologies and interface separations have been characterized by using the Atomic Force Microscope (AFM) and the Focused Ion Beam (FIB) imaging system. The lengths and amplitudes of numerous imperfections have been measured by AFM and the interface separations characterized on cross sections made with the FIB. Chemical analysis of several sites, performed using Auger Electron Spectroscopy (AES), has revealed the origin of the imperfections. The incidence of buckles has been correlated with the imperfection length.

Analysis of Cu(InGa)Se2 Alloy Film Optical Properties and the Effect of Cu Off-Stoichiometry

2005 ◽  
Vol 865 ◽  
Author(s):  
P. D. Paulson ◽  
S. H. Stephens ◽  
W. N. Shafarman
Keyword(s):  
Optical Constants ◽  
Soda Lime ◽  
Alloy Film ◽  
Relative Volume ◽  
Soda Lime Glass ◽  
Distinctive Features ◽  
Glass Substrates ◽  
Wide Range ◽  
Two Phases

AbstractVariable angle spectroscopic ellipsometry has been used to characterize Cu(InGa)Se2 thin films as a function of relative Ga content and to study the effects of Cu off-stoichiometry. Uniform Cu(InGa)Se2 films were deposited on Mo-coated soda lime glass substrates by elemental evaporation with a wide range of relative Cu and Ga concentrations. Optical constants of Cu(InGa)Se2 were determined over the energy range of 0.75–C4.6 eV for films with 0 ≤ Ga/(In+Ga) ≤ 1 and used to determine electronic transition energies. Further, the changes in the optical constants and electronic transitions as a function of Cu off-stoichiometry were determined in Cu-In-Ga-Se films with Cu atomic concentration varying from 10 to 25 % and Ga/(In+Ga) = 0.3. Films with Cu in the range 16–24 % are expected to contain 2 phases so an effective medium approximation is used to model the data. This enables the relative volume fractions of the two phases, and hence composition, to be determined. Two distinctive features are observed in the optical spectra as the Cu concentration decreases. First, the fundamental bandgaps are shifted to higher energies. Second, the critical point features at higher energies become broader suggesting degradation of the crystalline quality of the material.

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