scholarly journals Study of Short-Range Motion of Atomic Hydrogen in Amorphous Silicon by Neutron Reflectometry

1992 ◽  
Vol 258 ◽  
Author(s):  
W. D. Dozier ◽  
K. W. Herwig ◽  
R. Shinar ◽  
H. Jia ◽  
J. Shinar
Keyword(s):  
Thin Films ◽  
Amorphous Silicon ◽  
Atomic Hydrogen ◽  
Short Distance ◽  
Short Range ◽  
High Density ◽  
Neutron Reflectometry ◽  
Preliminary Results ◽  
Sputter Deposited ◽  
Nominal Resolution

ABSTRACTPreliminary results of neutron reflectometry (NR) measurements on if sputter-deposited a-Si:H/a-Si:D bilayers indicate that this technique may be used to monitor H and D motions over distances of ≈ 10 to 200 Å with a nominal resolution of 5 – 10 Å. In studying rf sputter-deposited thin films containing a high density of microvoids annealed at 270 C, we found that the hydrogen diffused a distance of only ≈ 100 Å. Further annealing at 270 and 280 C produced no additional motion. This result is consistent with a model of this system in which the hydrogen is trapped in microvoids after moving a relatively short distance.

Diffusion in Isotope Heterostructures Investigated by Neutron Reflectometry

2009 ◽  
Vol 289-292 ◽  
pp. 697-703 ◽  
Author(s):  
Erwin Hüger ◽  
Jochen Stahn ◽  
Udo Geckle ◽  
Michael Bruns ◽  
Harald Schmidt
Keyword(s):  
Thin Films ◽  
Silicon Nitride ◽  
Amorphous Silicon ◽  
Model System ◽  
Neutron Reflectometry ◽  
Diffusion In Solids ◽  
Amorphous Silicon Nitride ◽  
Self Diffusion

Studies of self-diffusion in solids are presented, which are based on neutron reflectometry. For the application of this technique the samples under investigation are prepared in form of isotope heterostructures. These are nanometer sized thin films, which are chemically completely homogenous, but isotope modulated. Using this method, diffusion lengths in the order of 1 nm and below can be detected which allows to determine ultra low diffusivities in the order of 10-25 m2/s. For the model system amorphous silicon nitride we demonstrate how the structure of the isotope hetrostructures (triple layers or multilayers) influences the efficiency of diffusivity determination.

Annealing of Irreversible Defects in Hydrogenated and Unhydrogenated Amorphous Silicon Thin Films

1990 ◽  
Vol 192 ◽  
Author(s):  
G. N. Parsons ◽  
C. Wang ◽  
G. Lucovsky
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Substrate Temperature ◽  
Amorphous Silicon ◽  
Time Constant ◽  
Annealing Time ◽  
Atomic Hydrogen ◽  
Characteristic Time ◽  
Silicon Thin Films ◽  
Anneal Time

ABSTRACTWe have prepared unhydrogenated and hydrogenated ([H] = 14 at.%) amorphous silicon thin films using magnetron sputtering with substrate temperature, TS = 40°C. After deposition, the films were annealed at temperatures between 150 and 200°C and conductivity was measured as a function of anneal time. We find that for that for both materials, the conductivity changes non-exponentially with annealing time. The characteristic time constant for annealing at 175°C is approximately the same in unhydrogenated films (τ≈100min) as found in films containing 14 atomic % hydrogen (τ≈200min).

Nucleation in Amorphous Si:H Alloy

1988 ◽  
Vol 100 ◽  
Author(s):  
Y. C. Koo ◽  
A. R. Perrin ◽  
K. T. Aust ◽  
S. Zukotynski
Keyword(s):  
Thin Films ◽  
Ion Implantation ◽  
Amorphous Silicon ◽  
Neutron Irradiation ◽  
Amorphous Material ◽  
Hydrogenated Amorphous Silicon ◽  
Neutron Radiation ◽  
Preliminary Results ◽  
Hydrogenated Amorphous ◽  
Microcrystalline Material

ABSTRACTA method of producing microcrystalline material from thin films of hydrogenated amorphous silicon was investigated. Exposure to gamma and neutron radiation, and silicon self ion implantation were used to induce nucleation in the amorphous material. According to the preliminary results, neutron irradiation represents a most promising method for promoting crystallization.

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