Temperature dependent refractive index of amorphous silicon determined by time-resolved reflectivity during low fluence excimer laser heating

2006 ◽  
Vol 99 (6) ◽  
pp. 063516 ◽  
Author(s):  
J. D. Hoyland ◽  
D. Sands
Keyword(s):  
Refractive Index ◽  
Amorphous Silicon ◽  
Excimer Laser ◽  
Laser Heating ◽  
Temperature Dependent ◽  
Time Resolved

Effects of Impurities on the Competition between Solid Phase Epitaxy and Random Crystallization In Ion-Implanted Silicon

1984 ◽  
Vol 35 ◽  
Author(s):  
G.L. Olson ◽  
J.A. Roth ◽  
Y. Rytz-Froidevaux ◽  
J. Narayan
Keyword(s):  
Laser Heating ◽  
Crystallization Process ◽  
Solid Phase ◽  
Crystallization Rate ◽  
Solid Phase Epitaxy ◽  
Temperature Dependent ◽  
Kinetics Parameters ◽  
Time Resolved ◽  
Cw Laser ◽  
Ion Implanted

ABSTRACTThe temperature dependent competition between solid phase epitaxy and random crystallization in ion-implanted (As+, B+, F+, and BF2+) silicon films is investigated. Measurements of time-resolved reflectivity during cw laser heating show that in the As+, F+, and BF2+-implanted layers (conc 4×1020cm-3) epitaxial growth is disrupted at temperatures 1000°C. This effect is not observed in intrinsic films or in the B+-implanted layers. Correlation with results of microstructural analyses and computer simulation of the reflectivity experiment indicates that disruption of epitaxy is caused by enhancement of the random crystallization rate by arsenic and fluorine. Kinetics parameters for the enhanced crystallization process are determined; results are interpreted in terms of impurity-catalyzed nucleation during the random crystallization process.

Excimer Laser Induced Crystallization of Amorphous Silicon-Germanium Films

1993 ◽  
Vol 321 ◽  
Author(s):  
A. Slaoui ◽  
C. Deng ◽  
S. Talwar ◽  
J. K. Kramer ◽  
B. Prevot ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Excimer Laser ◽  
Silicon Germanium ◽  
Laser Energy ◽  
Electron Gun ◽  
Laser Crystallization ◽  
Time Resolved ◽  
Si Substrates ◽  
Si Films ◽  
Amorphous Silicon Germanium

ABSTRACTApplication of excimer laser crystallization of Amorphous silicon (a-Si) has introduced a new, interesting potential technology for the fabrication of polycrystalline (poly-Si) thin film transistors. We are currently studying polycrystalline Si1−xGex thin films in order to determine whether this material can lead to improved electrical properties or to better processing requirements when compared with polycrystalline Si films. In this work we analyze by RBS, TEM, Raman spectroscopy and surface reflectance, the structure of thin Amorphous Si1−xGex films after irradiation with a XeCl excimer laser. The Amorphous SiGe films were prepared by evaporation of Si and Ge onto oxidized Si substrates using an electron gun in vaccum. The effects of laser energy fluence during irradiation are investigated. The Amorphous to crystalline transition is followed by in-situ measurement of time-resolved reflectivity.

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.

Regrowth Rates of Amorphous Layers in Silicon-on-Sapphire Films

1985 ◽  
Vol 52 ◽  
Author(s):  
P. J. Timans ◽  
R. A. McMahon ◽  
H. Ahmed
Keyword(s):  
Refractive Index ◽  
Electron Beam ◽  
Temperature Dependence ◽  
Amorphous Silicon ◽  
Amorphous Layer ◽  
Heating Cycle ◽  
Isothermal Heating ◽  
Time Resolved ◽  
Infra Red ◽  
High Absorption

ABSTRACTThe rate and direction of regrowth of amorphous layers, created by self-implantation, in silicon-on-sapphire (SOS) have been studied using time resolved reflectivity (TRR) experiments performed simultaneously at two wavelengths. Regrowth of an amorphous layer towards the surface was observed in specimens implanted with 3.1015Si+/cm2 at 50keV and regrowth of a buried amorphous layer, from a surface seed towards the sapphire, was observed in specimens implanted with 1.1015Si+/cm2 at 175keV. Rapid isothermal heating to regrow the layers was performed in an electron beam annealing system. The combination of 514.5nm and 632.8nm wavelengths was found to be particularly useful for TRR studies since the high absorption in amorphous silicon, at the shorter wavelength, means that the TRR trace is not complicated by reflection from the silicon-sapphire interface until regrowth is nearly complete. The dual wavelength method removes ambiguity about the position of the amorphous to crystalline interface and the direction of regrowth. The temperature dependence of the refractive index of silicon leads to large changes in the reflectivity of SOS films as they are heated. The combination of regrowth rate observations and reflectivity measurements during heating has been used to characterize the isothermal heating cycle, avoiding the difficulties of using pyrometers operating at the useful near infra-red wavelengths, where sapphire is transparent.

Evidence Against a Reduced Melting Temperature in Amorphous Silicon

1981 ◽  
Vol 4 ◽  
Author(s):  
S.A. Kokorowski ◽  
G.L. Olson ◽  
J.A. Roth ◽  
L.D. Hess
Keyword(s):  
Melting Point ◽  
Amorphous Silicon ◽  
Melting Temperature ◽  
Laser Heating ◽  
Crystalline Silicon ◽  
Phase Changes ◽  
Experimental Results ◽  
Melting Point Depression ◽  
Time Resolved ◽  
Cw Laser

ABSTRACTExperimental results are presented which indicate that amorphous silicon does not melt at a temperature significantly lower than the melting point of crystalline silicon (1693°K), contrary to recent reports which suggest a 300 to 500°K melting point depression. Time-resolved optical reflectivity measurements are used to determine the temperature and to investigate phase changes which occur in silicon during cw laser heating. It is shown that amorphous silicon films produced by arsenic implantation into Si(100) do not melt when heated to temperatures in excess of 1600°K. An alternate interpretation of previous work that is consistent with the present findings is proposed.

Temperature Dependent Kinetics of the OH/HO2/O3Chain Reaction by Time-Resolved IR Laser Absorption Spectroscopy

2000 ◽  
Vol 104 (17) ◽  
pp. 3964-3973 ◽  
Author(s):  
Sergey A. Nizkorodov ◽  
Warren W. Harper ◽  
Bradley W. Blackmon ◽  
David J. Nesbitt
Keyword(s):  
Absorption Spectroscopy ◽  
Laser Absorption Spectroscopy ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Laser Absorption ◽  
Ir Laser ◽  
Kinetics Of

scholarly journals The thermal stability of FAPbBr3 nanocrystals from temperature-dependent photoluminescence and first-principles calculations

RSC Advances ◽  
2020 ◽  
Vol 10 (72) ◽  
pp. 44373-44381
Author(s):  
Xiaozhe Wang ◽  
Qi Wang ◽  
Zhijun Chai ◽  
Wenzhi Wu
Keyword(s):  
First Principles ◽  
First Principle ◽  
First Principles Calculations ◽  
Temperature Dependent ◽  
Time Resolved ◽  
First Principle Calculations ◽  
Steady State Time ◽  
Time Resolved Photoluminescence ◽  
Thermal Stability Of ◽  
Temperature Dependent Photoluminescence

The thermal properties of FAPbBr3 perovskite nanocrystals (PNCs) is investigated by use of temperature-dependent steady-state/time-resolved photoluminescence and first-principle calculations.

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