The Structure of Ion-Implanted Amorphous Silicon

1998 ◽  
Vol 540 ◽  
Author(s):  
J. M. Gibson ◽  
J-Y. Cheng ◽  
P. Voyles ◽  
M.M.J. TREACY ◽  
D.C. Jacobson
Keyword(s):  
Amorphous Silicon ◽  
Network Model ◽  
Random Network ◽  
Amorphous Semiconductors ◽  
Range Order ◽  
Medium Range Order ◽  
Medium Range ◽  
Large Heat ◽  
Continuous Random Network ◽  
Ion Implanted

AbstractUsing fluctuation microscopy, we show that ion-implanted amorphous silicon has more medium-range order than is expected from the continuous random network model. From our previous work on evaporated and sputtered amorphous silicon, we conclude that the structure is paracrystalline, i.e. it possesses crystalline-like order which decays with distance from any point. The observation might pose an explanation for the large heat of relaxation that is evolved by ion-implanted amorphous semiconductors.

Observations of structural order in ion-implanted amorphous silicon

2001 ◽  
Vol 16 (11) ◽  
pp. 3030-3033 ◽  
Author(s):  
Ju-Yin Cheng ◽  
J. M. Gibson ◽  
D. C. Jacobson
Keyword(s):  
Electron Microscopy ◽  
Amorphous Silicon ◽  
Random Network ◽  
Dark Field ◽  
Range Order ◽  
Length Scale ◽  
Medium Range Order ◽  
Medium Range ◽  
Fluctuation Electron Microscopy ◽  
Ion Implanted

Medium-range order in ion-implanted amorphous silicon has been observed using fluctuation electron microscopy. In fluctuation electron microscopy, variance of dark-field image intensity contains the information of high-order atomic correlations, primarily in medium-range order length scale (1–3 nm). Thermal annealing greatly reduces the order and leaves a random network. It appears that the free energy change previously observed on relaxation may therefore be associated with randomization of the network. In this paper, we discuss the origin of the medium-range order during implantation, which can be interpreted as a paracrystalline state, that is, a disordered network enclosing compacts of highly topologically ordered grains on the length scale of 1–3 nm with significant strain fields.

Medium-Range Order of Amorphous Silicon Germanium Alloys: Small-Angle X-Ray Scattering Study

1989 ◽  
Vol 28 (Part 2, No. 7) ◽  
pp. L1092-L1095 ◽  
Author(s):  
Shin-ichi Muramatsu ◽  
Toshikazu Shimada ◽  
Hiroshi Kajiyama ◽  
Kazufumi Azuma ◽  
Takeshi Watanabe ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Small Angle ◽  
Silicon Germanium ◽  
Range Order ◽  
Medium Range Order ◽  
X Ray ◽  
X Ray Scattering ◽  
Medium Range ◽  
Scattering Study ◽  
Amorphous Silicon Germanium

On the influence of short and medium range order on the material band gap in hydrogenated amorphous silicon

2004 ◽  
Vol 96 (7) ◽  
pp. 3818-3826 ◽  
Author(s):  
A. H. Mahan ◽  
R. Biswas ◽  
L. M. Gedvilas ◽  
D. L. Williamson ◽  
B. C. Pan
Keyword(s):  
Amorphous Silicon ◽  
Band Gap ◽  
Hydrogenated Amorphous Silicon ◽  
Range Order ◽  
Medium Range Order ◽  
Medium Range ◽  
Hydrogenated Amorphous

Comparative Fluctuation Microscopy Study of Medium-Range Order in Hydrogenated Amorphous Silicon Deposited by Various Methods

2000 ◽  
Vol 609 ◽  
Author(s):  
P. M. Voyles ◽  
M. M. J. Treacy ◽  
H-C. Jin ◽  
J. R. Abelson ◽  
J. M. Gibson ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Amorphous Matrix ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
Range Order ◽  
Medium Range Order ◽  
Medium Range ◽  
Hydrogenated Amorphous

ABSTRACTWe have characterized by fluctuation electron microscopy the medium-range order of hydrogenated amorphous silicon thin films deposited by a variety of methods. Films were deposited by reactive magnetron sputtering, hot-wire chemical vapor deposition, and plasma enhanced chemical vapor deposition with and without H2 dilution of the SiH4 precursor gas. All of the films show the signature of the paracrystalline structure typical of amorphous Si. There are small variations in the degree of medium-range order with deposition method and H content. The PECVD film grown with high H2 dilution contains Si crystals ∼5 nm in diameter at a density of ∼109 cm−2. The amorphous matrix surrounding these crystals shows no difference in mediumrange order from the standard PECVD film. This supports explanations of the resistance of the H-dilution material to light-induced degradation that depend only on the presence of crystalline grains without modifications of the amorphous matrix.

Fluctuation Microscopy Studies of Medium-range Order Structures in Amorphous Tetrahedral Semiconductors

2000 ◽  
Vol 638 ◽  
Author(s):  
Xidong Chen ◽  
J. Murray Gibson ◽  
John Sullivan ◽  
Tom Friedmann ◽  
Paul Voyles
Keyword(s):  
Thermal Annealing ◽  
Random Network ◽  
Carbon Films ◽  
Range Order ◽  
Diamond Like Carbon ◽  
Medium Range Order ◽  
Microscopy Technique ◽  
Medium Range ◽  
Annealing Effects ◽  
Fluctuation Microscopy

AbstractWe applied fluctuation microscopy technique to study medium-range order in tetrahedral semiconductor materials, such as amorphous silicon, amorphous diamond-like carbon films. It is shown that this technique is very sensitive to local structure changes in the medium range order and promises solutions to open questions that cannot be answered by current techniques. For asdeposited amorphous germanium and silicon, we previously identified a fine-grain para-crystallite structure [1, 2], which will be relaxed into a lower-energy continuous random network structure after thermal annealing. With the same fluctuation microscopy technique, we however found that thermal annealing introduces medium-range order in amorphous diamond-like carbon films. Future studies will be focused on modeling and systematic exploration of annealing effects.

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