Nanosecond Time Resolution In Situ Optical Reflection and Transmission Measurements during XeF Excimer Laser Interaction with Amorphous Silicon Thin Films

2006 ◽  
Vol 505-507 ◽  
pp. 337-342 ◽  
Author(s):  
Chil Chyuan Kuo ◽  
W.C. Yeh ◽  
C.B. Chen ◽  
J.Y. Jeng
Keyword(s):  
Amorphous Silicon ◽  
Excimer Laser ◽  
Time Resolution ◽  
Reflection And Transmission ◽  
Time Resolved ◽  
Silicon Thin Films ◽  
Laser Fluences ◽  
Transmission Measurements ◽  
Nanosecond Time Resolution

XeF excimer laser-induced melting and recrystallization of amorphous silicon was studied using in-situ online time-resolved reflection and transmission measurements with a nanosecond time resolution. The explosive crystallization was observed for 50nm thick amorphous silicon on SiO2 deposited on non-alkali glass substrate upon 25ns pulse duration of excimer laser. Three distinct regrowth regimes were found using various excimer laser fluences. Scanning electron microscopy, Raman spectroscopy and atomic force microscopy were used to evaluate the excimer laser- irradiated region of the sample. Grain size, surface roughness and melt duration as a function of different laser fluences are also determined.

Time-Resolved Optical Studies of Amorphous CoSi Thin-Film Crystallization

1992 ◽  
Vol 280 ◽  
Author(s):  
M. Libera ◽  
T. Kim ◽  
K. Siangchaew ◽  
L. Clevenger ◽  
Q. Hong
Keyword(s):  
Kinetic Modelling ◽  
Optical Data ◽  
Optical Studies ◽  
Tem Analysis ◽  
Reflection And Transmission ◽  
Time Resolved ◽  
Transmission Electron ◽  
Transmission Measurements ◽  
Potential Use

ABSTRACTTime-resolved reflection and transmission measurements during heating are coupled with transmission electron microscopy (TEM) to study the crystallization of amorphous 75nm Co49Si51 films. The reflection decreases and the transmission increases upon crystallization. Optical data are converted to a measure of the fraction crystallized, χ=χ(T,t). A Kissinger analysis gives an activation energy for crystallization of 1.1 eV. TEM analysis of films crystallized in-situ show they are principally CoSi2 with a small amount of CoSi2. These results are being used for kinetic modelling of crystallization of amorphous Co-silicide films for potential use in Si mosfet and bipolar technologies.

Deposition and Crystallisation Behaviour of Amorphous Silicon Thin Films Obtained by Pyrolysis of Disilane Gas at Very Low Pressure

1994 ◽  
Vol 345 ◽  
Author(s):  
T. Kretz ◽  
D. Pribat ◽  
P. Legagneux ◽  
F. Plais ◽  
O. Huet ◽  
...  
Keyword(s):  
Activation Energy ◽  
Growth Rate ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Electrical Conductance ◽  
Chemical Vapor ◽  
Crystalline Fraction ◽  
Silicon Thin Films ◽  
Crystallisation Behaviour

AbstractHigh purity amorphous silicon layers were obtained by ultrahigh vacuum (millitorr range) chemical vapor deposition (UHVCVD) from disilane gas. The crystalline fraction of the films was monitored by in situ electrical conductance measurements performed during isothermal annealings. The experimental conductance curves were fitted with an analytical expression, from which the characteristic crystallisation time, tc, was extracted. Using the activation energy for the growth rate extracted from our previous work, we were able to determine the activation energy for the nucleation rate for the analysed-films. For the films including small crystallites we have obtained En ∼ 2.8 eV, compared to En ∼ 3.7 eV for the completely amorphous ones.

In situ excimer laser irradiation as cleaning tool for solid phase epitaxy of laser crystallized polycrystalline silicon thin films

2013 ◽  
Vol 210 (12) ◽  
pp. 2729-2735 ◽  
Author(s):  
Ingmar Höger ◽  
Thomas Schmidt ◽  
Anja Landgraf ◽  
Martin Schade ◽  
Annett Gawlik ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Irradiation ◽  
Excimer Laser ◽  
Polycrystalline Silicon ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Silicon Thin Films ◽  
Excimer Laser Irradiation

Nucleation Process During Excimer Laser Annealing of Amorphous Silicon Thin Films on Glass: A Molecular-dynamics Study

2006 ◽  
Vol 958 ◽  
Author(s):  
Shinji Munetoh ◽  
Takanori Mitani ◽  
Takahide Kuranaga ◽  
Teruaki Motooka
Keyword(s):  
Thin Films ◽  
Molecular Dynamics ◽  
Amorphous Silicon ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Surface Region ◽  
Excimer Laser Annealing ◽  
Silicon Thin Films ◽  
Steady State Temperature ◽  
Dynamics Simulations

ABSTRACTWe have performed molecular-dynamics simulations of heating, melting and recrystallization processes in amorphous silicon (a-Si) thin films deposited on glass during excimer laser annealing. By partially heating the a-Si surface region with 2 nm depth and removing thermal energy from the bottom of the glass substrate, a steady-state temperature profile was obtained in the a-Si layer with the thickness of 15 nm and only the surface region was melted. It was found that nucleation predominantly occurred in the a-Si region as judged by the coordination numbers and diffusion constants of atoms in the region. The results suggest that nucleation occurs in unmelted residual a-Si region during the laser irradiation and then crystal growth proceeds toward liquid Si region under the near-complete melting condition.

Low Temperature Crystallization of Amorphous Silicon Films Using an Excimer Laser

1989 ◽  
Vol 149 ◽  
Author(s):  
S. E. Ready ◽  
J. B. Boyce ◽  
R. Z. Bachrach ◽  
R. I. Johnson ◽  
K. Winer ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Excimer Laser ◽  
Laser Energy ◽  
Amorphous Material ◽  
Surface Region ◽  
Silicon Films ◽  
Starting Material ◽  
Near Surface ◽  
Silicon Thin Films ◽  
Crystallite Sizes

ABSTRACTIn an effort to enhance the electrical properties of silicon thin films, we have performed recrystallization experiments on a variety of amorphous silicon films using an excimer laser. The intense, pulsed UV produced by the laser (308nm, using XeCl gas) is highly absorbed by the amorphous material and thus provides intense localized heating in the near surface region. Two types of starting films were studied: plasma CVD a-Si:H and LPCVD a-Si. The subsequent modification produces crystallites whose structure and electrical characteristics vary due to starting material and laser scan parameters. The treated films have been characterized using Raman, x-ray diffraction, TEM, SIMS and transport measurements. The results indicate that crystallites nucleate in the surface region. The degree of crystallization near the surface increases dramatically as a function of deposited laser energy density and less so as a function of laser shot density. The hall mobility of the highly crystallized samples exhibit an increase of 2 orders of magnitude over the amorphous starting material. In the PECVD material, the rapid diffusion of hydrogen causes voids to be formed at intermediate laser energy densities and removal of film at higher energy densities. The LPCVD material withstands the high laser energies to produce well crystallized films with crystallite sizes greater then 1000Å.

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