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.

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.

Transient and Furnace Annealing of Ion Implanted Gallium Arsenide

1980 ◽  
Vol 1 ◽  
Author(s):  
J. S. Williams ◽  
H. B. Harrison
Keyword(s):  
Gallium Arsenide ◽  
Solid Phase ◽  
Pulsed Lasers ◽  
Physical Processes ◽  
Furnace Annealing ◽  
Annealing Behaviour ◽  
Cw Laser ◽  
Similarities And Differences ◽  
Solid Phase Regrowth ◽  
Ion Implanted

ABSTRACTThis review examines the annealing behaviour of ion implanted gallium arsenide during furance, laser and e-beam processing.The two annealing regimes, namely solid phase regrowth via furnace or CW laser/e-beam annealing and liquid phase epitaxy produced by pulsed lasers/e-beam, are examined in some detail.Emphasis is placed upon an understanding of the physical processes which are important during the various annealing modes.Comparison with the annealing behaviour of ion implantedelemental semiconductors(notably silicon) is made throughout the review to highlight relevant similarities and differences between compound and elemental semiconductors.The electrical properties of annealed gallium arsenide layers are not treatedin any detail, although particular observations which are relevant to the annealing processes are briefly discussed.

Direct Measurement of Cw Laser-Induced Crystal Growth Dynamics by Time-Resolved Optical Reflectivity

1980 ◽  
Vol 1 ◽  
Author(s):  
G.L. Olson ◽  
S.A. Kokorowski ◽  
J.A. Roth ◽  
L.D. Hess
Keyword(s):  
Crystal Growth ◽  
Solid Phase ◽  
Growth Dynamics ◽  
Time Resolved ◽  
Laser Method ◽  
Optical Reflectivity ◽  
Spatially Resolved ◽  
Use Of Time ◽  
Cw Laser

ABSTRACTWe report the use of time-resolved optical reflectivity to directly monitor the dynamics of cw laser-induced solid phase epitaxy (SPE) of thin films. This in situ measurement technique utilizes optical interference effects between light reflected from the surface of a sample and from an advancing interface to provide continuous temporal and spatial resolution of crystal growth processes. SPE growth rates of ionimplanted films which are five orders of magnitude faster than previously observed can be induced and accurately measured with the laser method. Arsenic enhances the SPE rate, and spatially resolved measurements show that the growth rate for arsenic implanted films varies in accordance with the ionimplantation profile. Results are reported for silicon selfimplanted samples with and without subsequent arsenic ion implantation, and for silicon samples directly implanted with arsenic.

Crystallization Kinetics of Fe-DOPED A1203

1994 ◽  
Vol 357 ◽  
Author(s):  
Todd W. Simpson ◽  
Ian V. Mitchell ◽  
Ning Yu ◽  
Michael Nastasi ◽  
Paul C. Mcintyre
Keyword(s):  
Crystallization Kinetics ◽  
Annealing Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Time Resolved ◽  
Α Phase ◽  
Kinetics Of ◽  
Beam Deposition

AbstractTime resolved optical reflectivity (TRR) and Rutherford backscattering spectrometry (RBS) and ion channelling methods have been applied to determine the crystallization kinetics of Fe-doped A1203 in the temperature range of 900-1050°C. Amorphous A1203 films, approximately 250 nm thick and with Fe cation concentrations of 0, 1.85, 2.2 and 4.5%, were formed by e-beam deposition on single crystal, [0001] oriented, A1203 substrates. Annealing was performed under an oxygen ambient in a conventional tube furnace, and the optical changes which accompany crystallization were monitored, in situ, by TRR with a 633nm wavelength laser.Crystallization is observed to proceed via solid phase epitaxy. An intermediate, epitaxial phase of -γ-Al203 is formed before the samples reach the ultimate annealing temperature. The 5% Fe-doped film transforms from γ to α-A1203 at a rate approximately 10 times that of the pure A1203 film and the 1.85% and 2.2% Fe-doped films transform at rates between these two extremes. The Fe-dopants occupy substitional lattice sites in the epilayer. Each of the four sets of specimens displays an activation energy in the range 5.0±0.2eV for the γ,α phase transition.

Ni-Induced Selective Nucleation and Solid Phase Epitaxy of Large-Grained Poly-Si on Glass

1999 ◽  
Vol 587 ◽  
Author(s):  
Rosaria A. Puglisi ◽  
Hiroshi Tanabe ◽  
Claudine M. Chen ◽  
Harry A. Atwater ◽  
Emanuele Rimini
Keyword(s):  
Amorphous Silicon ◽  
Polycrystalline Silicon ◽  
Crystalline Silicon ◽  
Solid Phase ◽  
Silicon Film ◽  
Crystallization Rate ◽  
Silicon Films ◽  
Solid Phase Epitaxy ◽  
Tem Analysis ◽  
Glass Substrates

AbstractWe investigated the formation of large-grain polycrystalline silicon films on glass substrates for application in low-cost thin film crystalline silicon solar cells. Since use of glass substrates constrains process temperatures, our approach to form large-grain polycrystalline silicon templates is selective nucleation and solid phase epitaxy (SNSPE). In this process, selective crystallization of an initially amorphous silicon film, at lithographically predetermined sites, enables grain sizes larger than those observed via random crystallization. Selective heterogeneous nucleation centers were created on undoped, 75 nm thick, amorphous silicon films, by masked implantation of Ni islands, followed by annealing at temperatures below 600 °. At this temperature, the Ni precipitates into NiSi2 particles that catalyze the transition from the amorphous to the crystalline Si phase. Seeded crystallization begins at the metal islands and continues via lateral solid phase epitaxy (SPE), thus obtaining crystallized regions of several tens of square microns in one hour. We have studied the dependence of the crystallization rate on the Ni-implanted dose in the seed, in the 5×1015/cm3 - 1016/cm3range. The large grained polycrystalline Si films were then used as a substrate for molecular beam epitaxy (MBE) depositions of 1 [.proportional]m thick Si layers. Transmission electron microscopy (TEM) analysis showed a strong correlation between the substrate morphology and the deposited layer. The layer presented a large grain morphology, with sizes of about 4 [.proportional]m.

Kinetics and Mechanisms of Solid Phase Epitaxy and Competitive Processes in Silicon

1984 ◽  
Vol 35 ◽  
Author(s):  
G.L. Olson
Keyword(s):  
Amorphous Silicon ◽  
Epitaxial Growth ◽  
Recent Progress ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Temperature Dependent ◽  
Solid Phase Crystallization ◽  
Induced Changes ◽  
Kinetics Of ◽  
Very High

ABSTRACTRecent progress in studies of temperature dependent kinetic competition during solid phase crystallization of silicon is reviewed. Specific areas which are emphasized include: the enhancement of solid phase epitaxial growth rates by impurity-induced changes in electronic properties at the crystal/amorphous interface, the influence of impurity diffusion and precipitation in amorphous silicon on the kinetics of epitaxial growth, the effects of impurities on the kinetic competition between solid phase epitaxy and random crystallization, and the kinetics of solid phase crystallization at very high temperatures in silicon.

Kinetics of Intrinsic and Dopant-Enhanced Solid Phase Epitaxy in Buried Amorphous Si Layers

1996 ◽  
Vol 439 ◽  
Author(s):  
J. C. McCallum
Keyword(s):  
Ion Implantation ◽  
Dopant Concentration ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Entire Concentration Range ◽  
Time Resolved ◽  
Amorphous Si ◽  
First Time ◽  
Kinetics Of ◽  
Suitable Environment

AbstractThe kinetics of intrinsic and dopant-enhanced solid phase epitaxy (SPE) have been measured in buried amorphous Si (a-Si) layers produced by ion implantation. Buried a-Si layers formed by self-ion implantation provide a suitable environment for studies of the intrinsic growth kinetics of amorphous Si, free from the rate-retarding effects of H. For the first time, dopant-enhanced SPE rates have been measured under these H-free conditions. Buried a-Si layers containing uniform As concentration profiles ranging from 1–16.1 × 1019 As.cm−3 were produced by multiple-energy ion implantation and time resolved reflectivity was used to measure SPE rates over the temperature range 480–660°C. In contrast to earlier studies, the dopant-enhanced SPE rate is found to depend linearly on the As concentration over the entire concentration range measured. The SPE rate can be expressed in the form, v/vi(T) = 1 + N/[No exp(-ΔE/kT)], where vi(T) is the intrinsic SPE rate, N is the dopant concentration and No = 1.2 × 1021 cm−3, ΔE = 0.21 eV.

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