Crystallization and Melting of Amorphous Silicon on a Microsecond Time Scale

1986 ◽  
Vol 74 ◽  
Author(s):  
G. L. Olson ◽  
J. A. Roth ◽  
E. Nygren ◽  
A. P. Pogany ◽  
J. S. Williams
Keyword(s):  
Film Thickness ◽  
Time Scale ◽  
Laser Heating ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Amorphous Films ◽  
Random Nucleation ◽  
Cw Laser ◽  
Time Regime ◽  
Amorphous Si

AbstractMeasurements of the competition beween solid phase epitaxy, solid phase random nucleation, and melting in amorphous Si on a microsecond time scale are reported. We find that the behavior of amorphous Si under microsecond pulsed dye laser irradiation depends strongly on film thickness and temperature. In “thin” (≲1000 Å) films solid phase epitaxy is observed at temperatures up to and exceeding 1300°C with random nucleation dominating at T>1330° C; however, melting of amorphous Si does not occur. In contrast, in “thick” (2600 Å) amorphous films melting is observed at T˜1190°C. These results are discussed with respect to measurements obtained previously in the nanosecond time regime using Q-switched laser heating and in the 0.1–1 millisecond regime using “chopped beam” cw laser heating.

Epitaxy and Nucleation in Cu and Ag Doped Amorphous Si

1990 ◽  
Vol 205 ◽  
Author(s):  
J. S. Custer ◽  
Michael O. Thompson ◽  
D. J. Eaglesham ◽  
D. C. Jacobson ◽  
J. M. Poate ◽  
...  
Keyword(s):  
Solid Phase ◽  
Amorphous Material ◽  
Intrinsic Rate ◽  
Amorphous Layer ◽  
Solid Phase Epitaxy ◽  
Small Deviations ◽  
Random Nucleation ◽  
Low Concentrations ◽  
Critical Metal ◽  
Amorphous Si

AbstractThe competition between solid phase epitaxy and random nucleation during thermal annealing of amorphous Si implanted with the fast diffusers Cu and Ag has been studied. For low concentrations of these impurities, solid phase epitaxy proceeds with small deviations from the intrinsic rate and with the impurity remaining in the shrinking amorphous layer. At a critical metal concentration in the amorphous layer of ∼ 0.12 at.% rapid random nucleation occurs, halting epitaxy and transforming the remaining amorphous material to polycrystalline Si via grain growth. The nucleation rate is at least 8 orders of magnitude greater than the intrinsic homogeneous rate. At higher Cu concentrations nucleation is observed below the temperature needed for epitaxy (400°C). This nucleation, clearly caused by the presence of Cu or Ag in the layer, may be induced by the impurities exceeding the absolute stability concentration and starting to phase separate, leading to enhanced crystal Si nucleation in the metal rich regions.

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.

Epitaxial growth versus nucleation in amorphous Si doped with Cu and Ag

1993 ◽  
Vol 8 (4) ◽  
pp. 820-829 ◽  
Author(s):  
J.S. Custer ◽  
Michael O. Thompson ◽  
D.J. Eaglesham ◽  
D.C. Jacobson ◽  
J.M. Poate
Keyword(s):  
Epitaxial Growth ◽  
Solid Phase ◽  
Intrinsic Rate ◽  
Amorphous Layer ◽  
Solubility Limit ◽  
Solid Phase Epitaxy ◽  
Metal Impurities ◽  
Random Nucleation ◽  
Si Doped ◽  
Amorphous Si

The competition between solid phase epitaxy and random nucleation in amorphous Si implanted with Cu and Ag has been studied. At low metal concentrations, solid phase epitaxy proceeds with slight deviations from the intrinsic rate, with the impurity segregated and evenly distributed in the amorphous layer. At an impurity concentration of 0.12 at.%, rapid nucleation occurs, transforming the remaining layer into polycrystalline Si. The nucleation rate is ≥108 the intrinsic homogeneous rate. The effects of the metals on epitaxy scale with the amount of metal–Si interaction. Nucleation appears to occur when the metal impurities exceed their absolute solubility limit and begin to phase separate.

Kinetics of solid phase epitaxy in thick amorphous Si layers formed by MeV ion implantation

1990 ◽  
Vol 57 (13) ◽  
pp. 1340-1342 ◽  
Author(s):  
J. A. Roth ◽  
G. L. Olson ◽  
D. C. Jacobson ◽  
J. M. Poate
Keyword(s):  
Ion Implantation ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Amorphous Si ◽  
Kinetics Of

Solid Phase Heteroepitaxy of Barium Ferrite on Sapphire

1992 ◽  
Vol 280 ◽  
Author(s):  
Michael A. Parker ◽  
T. L. Hylton ◽  
K. R. Coffey ◽  
J. K. Howard
Keyword(s):  
Film Thickness ◽  
Barium Ferrite ◽  
Solid Phase ◽  
Amorphous Films ◽  
New Process ◽  
Dimensional Growth

ABSTRACTA new process for the crystallization of amorphous films on chemically dissimilar substrates, solid phase heteroepitaxy (SPHE), is described. Unlike SPE in Si, it is found that the kinetics can be modeled by nucleation and multi-dimensional growth with Johnson-Mehl kinetics modified for the effects of a finite film thickness and nucleation initiated at the interface with the substrate.

Amorphous‐Si/crystalline‐Si facet formation during Si solid‐phase epitaxy near Si/SiO2 boundary

1984 ◽  
Vol 56 (2) ◽  
pp. 279-285 ◽  
Author(s):  
Yasuo Kunii ◽  
Michiharu Tabe ◽  
Kenji Kajiyama
Keyword(s):  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Amorphous Si ◽  
Facet Formation

Lateral Solid Phase Epitaxy of Amorphous Si Films under Ultrahigh Pressure

1992 ◽  
Author(s):  
H. Ishiwara ◽  
H. Wakabayashi ◽  
K. Miyazaki ◽  
K. Fukao ◽  
A. Sawaoka
Keyword(s):  
Solid Phase ◽  
Ultrahigh Pressure ◽  
Solid Phase Epitaxy ◽  
Amorphous Si ◽  
Si Films

Polycrystalline Si Films Fabricated by Low Temperature Selective Nucleation and Solid Phase Epitaxy Process

1997 ◽  
Vol 485 ◽  
Author(s):  
Claudine M. Chen ◽  
Harry A. Atwater
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Crystal Growth ◽  
Incubation Time ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Grain Sizes ◽  
Random Nucleation ◽  
Nucleation Sites ◽  
Si Films

AbstractWith a selective nucleation and solid phase epitaxy (SNSPE) process, grain sizes of 10 μm have been achieved to date at 620°C in 100 nrm thick silicon films on amorphous SiO2, with potential for greater grain sizes. Selective nucleation occurs via a thin film reaction between a patterned array of 20 rnm thick indium islands which act as heterogeneous nucleation sites on the amorphous silicon starting material. Crystal growth proceeds by lateral solid phase epitaxy from the nucleation sites, during the incubation time for random nucleation. The largest achievable grain size by SNSPE is thus approximately the product of the incubation time and the solid phase epitaxy rate. Electronic dopants, such as B, P, and Al, are found to enhance the solid phase epitaxy rate and affect the nucleation rate.

Boron Doping Effects in Lateral Solid Phase Epitaxy of Amorphous Si Films

1985 ◽  
Vol 24 (Part 2, No. 7) ◽  
pp. L513-L515 ◽  
Author(s):  
Hiroshi Ishiwara ◽  
Akihiro Tamba ◽  
Hiroshi Yamamoto ◽  
Seijiro Furukawa
Keyword(s):  
Solid Phase ◽  
Boron Doping ◽  
Solid Phase Epitaxy ◽  
Doping Effects ◽  
Amorphous Si ◽  
Si Films

Heteroepitaxial Growth of Strontium Titanate on Lanthanum Aluminate Using the Metallo-Organic Decomposition Technique.

1993 ◽  
Vol 317 ◽  
Author(s):  
Gabriel Braunstein ◽  
Gustavo R. Paz-Pujalt ◽  
James F. Elman
Keyword(s):  
Solid Phase ◽  
Precursor Solution ◽  
Solid Phase Epitaxy ◽  
Heteroepitaxial Growth ◽  
Potential Influence ◽  
Ion Channeling ◽  
Random Nucleation ◽  
Lanthanum Aluminate ◽  
Organic Precursors ◽  
Organic Decomposition

ABSTRACTWe demonstrate the heteroepitaxial growth of thin films of SrTiO3 prepared by the method of Metallo-organic decomposition on LaAlO3 substrates. The SrTiO3 films are prepared by spin coating and thermal decomposition of a solution of Metallo-organic precursors on single-crystal, <100> oriented, LaAK>3 substrates. Subsequent heat treatment at 1100 – 1200 °C for 1 h results in the epitaxial alignment of the SrTiO3 films with respect to the LaAlO3 substrate.The degree of alignment of the films appears to depend on their thickness, with thinner films showing better alignment (as determined by ion-channeling measurements). This behavior is interpreted as a result of the competition between solid-phase epitaxy and random nucleation, observed during the crystallization of films prepared by Metallo-organic decomposition. However, since thinner films have been prepared by dilution of the precursor solution, there is also the possibility that the concentration of the precursor solution may influence the crystallization behavior of the films.The potential influence of the precursor formulation on the crystallization mechanism is discussed.

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