Effect of oxygen on nanoscale indentation-induced phase transformations in amorphous silicon

AbstractIon-implantation has been used to introduce oxygen concentration-depth profiles into nominally oxygen-free amorphous silicon (a-Si). The effect of O concentrations in excess of 1018 cm−3 on the formation of high pressure crystalline phases (Si-III and Si-XII) during indentation unloading has been studied. By examination of unloading curves and post-indent Raman micro-spectroscopy O is found to inhibit the so-called pop-out event during unloading and, therefore, the formation of the crystalline phases. Furthermore, at high O concentrations (> 1021 cm−3) the formation of these phases is reduced significantly such that under indentation conditions used here the probability of forming the phases is reduced to almost zero. We suggest that the bonding of O with Si reduces the formation of Si-III/XII during unloading through a similar mechanism to that of oxygen-retarded solid phase crystallization of a-Si.

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Atomic structure of ion-implantation produced amorphous silicon and amorphous-crystalline interface structure and kinetics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074483 ◽

1983 ◽

Vol 41 ◽

pp. 122-123

Author(s):

J. Narayan ◽

D. Fathy

Keyword(s):

Solar Cells ◽

Ion Implantation ◽

Physical Properties ◽

Amorphous Silicon ◽

Crystallization Kinetics ◽

Atomic Structure ◽

Solid Phase ◽

Interface Structure ◽

Solid Phase Crystallization ◽

Two Factors

The structure of amorphous silicon determines its physical properties ranging from crystallization kinetics to efficiency of solar cells. One point of particular interest has been the existance of microcrystallites in the amorphous phase. Different crystallization kinetics are obtained for purely amorphous silicon and for amorphous silicon having a trace of crystallinity. The incorporation of dopants into substitutional sites after solid-phase crystallization has been also found to be affected by the degree of amorphousness.The purpose of this investigation was two fold: first, to characterize the structure of amorphous silicon, and second to study the structure of amorphous-crystalline interface. The importance of these two factors in the crystallization phenomena is discussed.

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Solid-Phase Crystallization of Amorphous Silicon Films

Advanced Topics in Crystallization ◽

10.5772/59723 ◽

2015 ◽

Cited By ~ 4

Author(s):

Dong Nyung Lee ◽

Sung Bo Lee

Keyword(s):

Amorphous Silicon ◽

Solid Phase ◽

Silicon Films ◽

Solid Phase Crystallization

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Effects of boron doping on solid phase crystallization of in situ doped amorphous Silicon thin films prepared by electron beam evaporation

Thin Solid Films ◽

10.1016/j.tsf.2019.137639 ◽

2020 ◽

Vol 694 ◽

pp. 137639 ◽

Cited By ~ 1

Author(s):

Salar H. Sedani ◽

Ozlen F. Yasar ◽

Mehmet Karaman ◽

Rasit Turan

Keyword(s):

Thin Films ◽

Electron Beam ◽

Amorphous Silicon ◽

Solid Phase ◽

Boron Doping ◽

Electron Beam Evaporation ◽

Solid Phase Crystallization ◽

Silicon Thin Films

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Stress Induced During the Solid-phase Crystallization of Amorphous Silicon Deposited by LPCVD

MRS Proceedings ◽

10.1557/proc-403-513 ◽

1995 ◽

Vol 403 ◽

Author(s):

T. Mohammed-Brahim ◽

K. Kis-Sion ◽

D. Briand ◽

M. Sarret ◽

F. Lebihan ◽

...

Keyword(s):

Amorphous Silicon ◽

Solid Phase ◽

Chemical Vapor ◽

In Situ Monitoring ◽

Crystallization Time ◽

Solid Phase Crystallization ◽

Pressure Chemical ◽

Hall Effect Measurements ◽

Deposition Techniques

AbstractThe Solid Phase Crystallization (SPC) of amorphous silicon films deposited by Low Pressure Chemical Vapor phase Deposition (LPCVD) using pure silane at 550'C was studied by in-situ monitoring the film conductance. The saturation of the conductance at the end of the crystallization process is found transient. The conductance decreases slowly after the onset of the saturation. This degradation is also observed from other analyses such as ellipsometry spectra, optical transmission and Arrhenius plots of the conductivity between 250 and 570K. Hall effect measurements show that the degradation is due to a decrease of the free carrier concentration n and not to a decrease of the mobility. This indicates a constant barrier height at the grain boundaries. The decrease of n is then due to a defect creation in the grain. Hence, whatever the substrate used, an optimum crystallization time exists. It depends on the amorphous quality film which is determined by the deposition techniques and conditions and on the crystallization parameters.

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Ion dose dependence on solid phase epitaxy of amorphous silicon carbide induced by ion implantation

MRS Proceedings ◽

10.1557/proc-742-k2.1 ◽

2002 ◽

Vol 742 ◽

Author(s):

In-Tae Bae ◽

Manabu Ishimaru ◽

Yoshihiko Hirotsu

Keyword(s):

Ion Implantation ◽

Amorphous Silicon ◽

Pair Distribution Function ◽

Solid Phase ◽

Dose Dependence ◽

Peak Intensity ◽

Transmission Electron ◽

Complete Recrystallization ◽

Atomistic Structure ◽

Sample Pair

ABSTRACTAmorphous silicon carbides (a-SiC) fabricated by Xe+ ion implantation into 6H-SiC (0001) to fluences of 1015 and 1016/cm2 have been annealed at 850 °C for 1 hour. Transmission electron microscopy (TEM) observations revealed that the 1015 Xe+/cm2 implanted sample was completely recrystallized, while most of the a-SiC remains in the 1016 Xe+/cm2 implanted sample. Pair-distribution function analyses of both of the as-implanted samples show that the peak intensity of Si-C heteronuclear bonds is higher and the peak intensities of Si-Si and C-C homonuclear bonds are lower in the 1015 Xe+/cm2 implanted sample, indicating that the atomistic structure of the 1015 Xe+/cm2 implanted sample is more chemically ordered than that of the 1016 Xe+/cm2 implanted sample. This result suggests that more chemically ordered atomistic structure of 1015 Xe+/cm2 implanted a-SiC leads to complete recrystallization during thermal annealing.

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Polycrystalline Silicon Films Formed by Solid-Phase Crystallization of Amorphous Silicon: the Substrate Effects on Crystallization Kinetics and Mechanism

MRS Proceedings ◽

10.1557/proc-424-243 ◽

1996 ◽

Vol 424 ◽

Cited By ~ 1

Author(s):

Y.-H. Song ◽

S.-Y. Kang ◽

K. I. Cho ◽

H. J. Yoo ◽

J. H. Kim ◽

...

Keyword(s):

Amorphous Silicon ◽

Solid Phase ◽

Chemical Vapor ◽

Solid Phase Crystallization ◽

Substrate Effects ◽

Random Nucleation ◽

Pressure Chemical ◽

Si Films ◽

Polycrystalline Silicon Films ◽

Induced Crystallization

AbstractThe substrate effects on the solid-phase crystallization of amorphous silicon (a-Si) have been extensively investigated. The a-Si films were prepared on two kinds of substrates, a thermally oxidized Si wafer (SiO2/Si) and a quartz, by low-pressure chemical vapor deposition (LPCVD) using Si2H6 gas at 470 °C and annealed at 600 °C in an N2 ambient for crystallization. The analysis using XRD and Raman scattering shows that crystalline nuclei are faster formed on the SiO2/Si than on the quartz, and the time needed for the complete crystallization of a-Si films on the SiO2/Si is greatly reduced to 8 h from ˜15 h on the quartz. In this study, it was first observed that crystallization in the a-Si deposited on the SiO2/Si starts from the interface between the a-Si film and the thermal oxide of the substrate, called interface-induced crystallization, while random nucleation process dominates on the quartz. The very smooth surface of the SiO2/Si substrate is responsible for the observed interface-induced crystallization of a-Si films.

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