Variable Energy Positron Annihilation Spectroscopy of GaN Grown on Sapphire Substrates with MOCVD

2005 ◽  
Vol 22 (5) ◽  
pp. 1214-1217 ◽  
Author(s):  
Hu Yi-Fan ◽  
C. D Beling ◽  
S Fung
Keyword(s):  
Positron Annihilation ◽  
Positron Annihilation Spectroscopy ◽  
Sapphire Substrates ◽  
Variable Energy

POSITRON INTERACTION IN POLYMERS

2004 ◽  
Vol 19 (23) ◽  
pp. 3951-3959 ◽  
Author(s):  
CORINE BAS ◽  
N. DOMINIQUE ALBÉROLA ◽  
MARIE-FRANCE BARTHE ◽  
JÉRÉMIE De BAERDEMAEKER ◽  
CHARLES DAUWE
Keyword(s):  
Positron Annihilation ◽  
Chemical Structure ◽  
Positron Beam ◽  
Positron Annihilation Spectroscopy ◽  
Hole Size ◽  
Doppler Broadening ◽  
Positron Source ◽  
Positron Annihilation Lifetime ◽  
Doppler Broadening Spectra ◽  
Variable Energy

A series of dense copolyimide membranes was characterized using positron annihilation spectroscopy. The positron annihilation lifetime spectroscopy performed on film with a classical positron source gives informations on the positronium fraction formed and also on the hole size within the film. The Doppler broadening spectra (DBS) of the gamma annihilation rays coupled with a variable energy positron beam allow the microstructural analyses as a function of the film depth. Experimental data were also linked to the chemical structure of the polyimides. It was found that the presence of the fluorine atoms strongly affects the positron annihilitation process and especially the DBS responses.

Study of nitrogen implanted amorphous hydrogenated carbon thin films by variable-energy positron annihilation spectroscopy

1997 ◽  
Vol 81 (5) ◽  
pp. 2451-2453 ◽  
Author(s):  
F. L. Freire ◽  
D. F. Franceschini ◽  
R. S. Brusa ◽  
G. R. Karwasz ◽  
G. Mariotto ◽  
...  
Keyword(s):  
Thin Films ◽  
Positron Annihilation ◽  
Positron Annihilation Spectroscopy ◽  
Carbon Thin Films ◽  
Amorphous Hydrogenated Carbon ◽  
Variable Energy

scholarly journals Probing the formation of silicon nano-crystals (Si-ncs) using variable energy positron annihilation spectroscopy

2011 ◽  
Vol 262 ◽  
pp. 012031 ◽  
Author(s):  
A P Knights ◽  
J D B Bradley ◽  
O Hulko ◽  
D V Stevanovic ◽  
C J Edwards ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Positron Annihilation Spectroscopy ◽  
Variable Energy

Characterization of Porous Silicate Low-k Films by Ellipsometric Porosimetry and Variable-energy Positron Annihilation Spectroscopy

2003 ◽  
Vol 788 ◽  
Author(s):  
Kenji Ito ◽  
Yoshinori Kobayashi ◽  
Ryoichi Suzuki ◽  
Toshiyuki Ohdaira ◽  
Runsheng Yu ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Positron Annihilation ◽  
Open Porosity ◽  
Average Pore Size ◽  
Relative Dielectric Constant ◽  
Positron Annihilation Spectroscopy ◽  
Dielectric Constants ◽  
Ellipsometric Porosimetry ◽  
Variable Energy

ABSTRACTWe a pplied ellipsometric porosimetry and variable-energy positron annihilation spectroscopy to the pore characterization of spin-on-glass silicon-oxide-backboned porous thin films with different relative dielectric constants between 2.3 and 3.2. It was found that the relative dielectric constant decreases linearly with increasing open porosity deduced by ellipsometric porosimetry. Comparison of the open porosity with the average pore size deduced by positron annihilation lifetime spectroscopy suggested that mesopores less contribute to open porosity and are not so effective in decreasing film relative dielectric constant in comparison with micropores.

Variable Energy Positron Annihilation Spectroscopy of Perovskite Oxides

2012 ◽  
Vol 331 ◽  
pp. 201-233 ◽  
Author(s):  
David J. Keeble
Keyword(s):  
Positron Annihilation ◽  
Oxygen Deficiency ◽  
Single Layer ◽  
Positron Annihilation Spectroscopy ◽  
Perovskite Oxide ◽  
Near Surface ◽  
Vacancy Defects ◽  
Positron Annihilation Lifetime ◽  
Primary Focus ◽  
Variable Energy

The application of variable energy positron annihilation spectroscopy (VE-PAS) methods to the study of perovskite oxide, ABO3, material thin films and near-surface regions is reviewed. The primary focus is on ferroic perovskite titanate oxide materials SrTiO3and Pb (ZrxTi1-x)O3, but studies of BaTiO3, LaxSr1-xCoO3, La0.67Sr0.33MnO3and YBa2CuO7-δare also included. Characterization of single layer and multilayer structures is discussed. The methods, in particular positron annihilation lifetime spectroscopy, allow the identification of cation vacancy defects at both the A-and B-sites with parts per million sensitivity. Varying oxygen deficiency is often observed to result in marked changes in PAS spectra; these effects are reviewed and discussed.

Study of Pore Architecture in Silicon Oxide Thin Films by Variable-energy Positron Annihilation Spectroscopy

2002 ◽  
Vol 751 ◽  
Author(s):  
Kenji Ito ◽  
Yoshinori Kobayashi ◽  
Runsheng Yu ◽  
Kouichi Hirata ◽  
Hisashi Togashi ◽  
...  
Keyword(s):  
Thin Films ◽  
Porous Silicon ◽  
Integrated Circuits ◽  
Positron Annihilation ◽  
Large Scale ◽  
Silicon Oxide ◽  
Positron Annihilation Spectroscopy ◽  
Oxide Thin Films ◽  
Intensive Investigation ◽  
Variable Energy

ABSTRACTApplication of porous silicon oxide thin films to nanotechnology is under intensive investigation. Introducing a large amount of nano pores into a silicon oxide matrix is important to develop low-k dielectrics for future ultra-large-scale integrated circuits (ULSI). In this work, we applied variable-energy positron annihilation to the characterization of porous silicon oxide thin films fabricated on silicon wafers by sputtering and spincoating. It was found that the sputtered film has higher open pore connectivity than that of the spincoated low-k film.

Sign in / Sign up

Export Citation Format

Share Document