Controlling the Nucleation Site and Crystal Orientation during Eximer-laser Annealing Processes in Thin Amorphous Si Films on Glass: A Molecular-dynamics Study

2019 ◽  
Vol 8 (1) ◽  
pp. 191-196
Author(s):  
Teruaki Motooka ◽  
Shinji Munetoh ◽  
Ryuzou Kishikawa ◽  
Tomonori Mitani ◽  
Tomohiko Ogata
Keyword(s):  
Molecular Dynamics ◽  
Crystal Orientation ◽  
Laser Annealing ◽  
Nucleation Site ◽  
Amorphous Si ◽  
Eximer Laser ◽  
Si Films

Crystallization Processes of Amorphous Si During Excimer Laser Annealing in Complete-melting and Near-complete-Melting Conditions: A Molecular Dynamics Study

2008 ◽  
Vol 1150 ◽  
Author(s):  
Tomohiko Ogata ◽  
Takanori Mitani ◽  
Shinji Munetoh ◽  
Teruaki Motooka
Keyword(s):  
Molecular Dynamics ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Irradiation Time ◽  
Md Simulations ◽  
Melting Rate ◽  
Excimer Laser Annealing ◽  
Complete Melting ◽  
Amorphous Si ◽  
Melting Conditions

AbstractWe investigated crystallization processes of amorphous Si (a-Si) during the excimer laser annealing in the complete-melting and near-complete-melting conditions by using molecular dynamics simulations. The initial a-Si configuration was prepared by quenching liquid Si (l-Si) in a MD cell with a size of 50×50×150Å3 composed of 18666 atoms. KrF excimer laser (wavelength: 248nm) annealing processes of a-Si were calculated by taking account of the change in the optical constant upon melting during a laser pulse shot with the intensity Ioexp[−(t–t0)2/ς2] (Io: laser fluence, t: irradiation time). The refractive indices of a-Si and l-Si were set at n+ik=1.0+3.0i and n+ik=1.8+3.0i, respectively. The simulated results well reproduced the observed melting rate and the near-complete-melting and complete-melting conditions were obtained for Io = 160mJ/cm2 and 180mJ/cm2, respectively. It was found that larger grains were obtained in the near-complete-melting condition. Our MD simulations also suggest that nucleation occurs first in a-Si and subsequent crystallization proceeds toward l-Si in the near-complete-melting case.

Molecular Dynamics Simulations of Nucleation and Crystallization Processes During Excimer-Laser Annealing of Amorphous Silicon on Glass

2003 ◽  
Vol 780 ◽  
Author(s):  
T. Motooka ◽  
S. Munetoh ◽  
Lee Byoung Min ◽  
K. Nisihira
Keyword(s):  
Molecular Dynamics ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Md Simulations ◽  
Lateral Growth ◽  
Crystal Surfaces ◽  
Excimer Laser Annealing ◽  
Crystalline Films ◽  
Dynamics Simulations ◽  
Si Films

AbstractWe have investigated atomistic processes of nucleation and crystallization in excimer-laser annealed thin Si films on glass based on molecular-dynamics (MD) simulations using the Tersoff potential. MD cells composed of up to approximately 50000 Si atoms were heated to produce melted Si, and then melted Si was quenched under various supercooled conditions with or without a temperature gradient and the corresponding nucleation processes were visualized. Lateral growth of thin Si crystalline films was also simulated by embedding a crystalline nano-particle with various crystal surfaces in melted Si. It has been found that the crystal surfaces become predominantly {111} during the lateral growth processes.

Competition Between Solid Phase Epitaxy and Random Crystallization During cw Laser Annealing of Amorphous Si Films

1981 ◽  
Vol 4 ◽  
Author(s):  
J.A. Roth ◽  
S.A. Kokorowski ◽  
G.L. Olson ◽  
L.D. Hess
Keyword(s):  
Laser Annealing ◽  
Volume Fraction ◽  
Solid Phase ◽  
Rapid Heating ◽  
Film Deposition ◽  
Solid Phase Epitaxy ◽  
Laser Crystallization ◽  
Amorphous Si ◽  
Si Films ◽  
Kinetics Of

ABSTRACTThe kinetics of amorphous-to-polycrystalline conversion and solid phase epitaxy (SPE) in UHV-deposited Si films have been determined over a wide temperature range by the use of optical reflectivity measurements made during rapid heating by a cw Ar laser. Crystallization rates measured in UHV following film deposition are reported and compared to rates measured in air in order to elucidate the effects of contaminants on the processes. The effects of boron doping on nucleation and growth kinetics are also reported. The crystallization rates determined in these studies can be used to predict the volume fraction of polycrystalline material formed during laserinduced SPE growth of thick epitaxial layers.

Effect of Substrate Heating During Excimer Laser Annealing on Poly-Si TFT

1995 ◽  
Vol 403 ◽  
Author(s):  
T. Noguchi ◽  
A. J. Tang ◽  
J. A. Tsai ◽  
R. Reif
Keyword(s):  
Energy Density ◽  
Laser Annealing ◽  
Single Pulse ◽  
Single Shot ◽  
Excimer Laser Annealing ◽  
Substrate Heating ◽  
Amorphous Si ◽  
Voltage Swing ◽  
Si Films ◽  
Low Temperature Process

AbstractSingle-shot ELA was performed on 45nm-thick amorphous Si films. With an increase in pulse energy density, the cystallinity improved drastically for both samples without heating and with heating at 400°C. Correspondingly, the characteristics of TFT fabricated using a low temperature process improved distinctly. The threshold voltage decreased depending on the decrease in gate voltage swing due to the improvement in crystallinity of Si films. Efficient single-pulse ELA of less than 250MJ/cm2 as the optimum condition for poly Si TFT has been attained as a result of saving an energy amount of 100mJ/cm2 by heating the substrate. Moreover, a uniform distribution of TFT characteristics across the wafer was obtained.

Growth of near noble metal Pd and Pt thin film silicides morphology and structure

1984 ◽  
Vol 42 ◽  
pp. 498-499
Author(s):  
E. I. Alessandrini ◽  
M. O. Aboelfotoh
Keyword(s):  
Noble Metals ◽  
Annealing Temperature ◽  
Chemical Compounds ◽  
Barrier Properties ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Stable Chemical ◽  
Metal Thickness ◽  
Amorphous Si ◽  
Si Films

Considerable interest has been generated in solid state reactions between thin films of near noble metals and silicon. These metals deposited on Si form numerous stable chemical compounds at low temperatures and have found applications as Schottky barrier contacts to silicon in VLSI devices. Since the very first phase that nucleates in contact with Si determines the barrier properties, the purpose of our study was to investigate the silicide formation of the near noble metals, Pd and Pt, at very thin thickness of the metal films on amorphous silicon.Films of Pd and Pt in the thickness range of 0.5nm to 20nm were made by room temperature evaporation on 40nm thick amorphous Si films, which were first deposited on 30nm thick amorphous Si3N4 membranes in a window configuration. The deposition rate was 0.1 to 0.5nm/sec and the pressure during deposition was 3 x 10 -7 Torr. The samples were annealed at temperatures in the range from 200° to 650°C in a furnace with helium purified by hot (950°C) Ti particles. Transmission electron microscopy and diffraction techniques were used to evaluate changes in structure and morphology of the phases formed as a function of metal thickness and annealing temperature.

Pulsed Laser Annealing of R.F.Sputtered Amorphous Si : H.Films, Doped with Arsenic

1981 ◽  
Vol 4 ◽  
Author(s):  
E. Fogarassy ◽  
R. Stuck ◽  
M. Toulemonde ◽  
P. Siffert ◽  
J.F. Morhange ◽  
...  
Keyword(s):  
Ruby Laser ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Amorphous Layer ◽  
High Concentration ◽  
Topographic Analysis ◽  
Pulsed Laser Annealing ◽  
Residual Hydrogen ◽  
Silicon Target ◽  
Amorphous Si

Arsenic doped amorphous silicon layers have been deposited on silicon single crystals by R.F.cathodic sputtering of a silicon target in a reactive argon-hydrogen mixture, and annealed with a Q-switched Ruby laser. Topographic analysis of the irradiated layers has shown the formation of a crater, due to an evaporation effect of material which could be related to the presence of a high concentration of Ar in the amorphous layer. RBS and Raman Spectroscopy showed that the remaining layer is not recrystallised probably due to inhibition by the residual hydrogen. However, it was found that arsenic diffuses into the monocrystalline substrate by laser induced diffusion of dopant from the surface solid source, leading to the formation of good quality P-N junctions.

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