Substrate Effects on the Kinetics of Solid Phase Crystallization In a-Si

1991 ◽  
Vol 230 ◽  
Author(s):  
L. Haji ◽  
P. Joubert ◽  
M. Guendouz ◽  
N. Duhamel ◽  
B. Loisel
Keyword(s):  
Indium Tin Oxide ◽  
Solid Phase ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Solid Phase Crystallization ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Drastic Effect ◽  
Kinetics Of

AbstractThe effect of substrate nature on the solid phase crystallization at 600 °C of a-Si deposited by low pressure chemical vapor deposition is investigated by x-ray diffraction and transmission electron microscopy. The nucleation rate varies slightly resulting to a weak variation in the final grain sizes as a function of the substrate type. In all cases the grain growth mode is found to be three dimensional. In contrary, a drastic effect of the substrate is observed for films deposited by plasma enhanced CVD. Fast crystallization is obtained on indium tin oxide (ITO) resulting to small grain poly-Si, whereas the crystallization is retarded on glass leading to an increase in the grain size.

Growth of Si1−xGex, Strained Layers Using Atmospheric-Pressure CVD

1991 ◽  
Vol 220 ◽  
Author(s):  
F. Namavar ◽  
J. M. Manke ◽  
E. P. Kvam ◽  
M. M. Sanfacon ◽  
C. H. Perry ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Defect Density ◽  
Chemical Vapor ◽  
Good Growth ◽  
X Ray Diffraction ◽  
Strained Layers ◽  
Dislocation Glide ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Film Defect

ABSTRACTThe objective of this paper is to demonstrate the epitaxial growth of SiGe strained layers using atmospheric-pressure chemical vapor deposition (APCVD). We have grown SiGe layers with various thicknesses and Ge concentrations at temperatures ranging from 800–1000°C. The samples were studied using a variety of methods, including transmission electron microscopy (TEM), high resolution X-ray diffraction (HRXRD) and Raman spectroscopy (RS). Both HRXRD and RS results indicate that samples with about 10% Ge and a thickness of about 1000 Å are almost fully strained. TEM analyses of these samples indicate a film defect density less than 105/cm2. SIMS results indicate that the oxygen concentration in the epitaxial layers is lower than that found in CZ substrates.Our analyses also indicate that as-grown epitaxial Ge layers several microns thick have a defect density less than 107/cm2. The relatively low defect density in both SiGe and Ge layers grown on Si has been attributed to far higher dislocation glide velocity at the relatively elevated growth temperatures employed in CVD and to very good growth cleanliness.

Growth of Silicon-Germanium Alloys by Atmospheric-Pressure Chemical Vapor Deposition at Low Temperatures

1991 ◽  
Vol 220 ◽  
Author(s):  
P. D. Agnello ◽  
T. O. Sedgwick ◽  
M. S. Goorsky ◽  
J. Ott ◽  
T. S. Kuan ◽  
...  
Keyword(s):  
Silicon Germanium ◽  
Atmospheric Pressure ◽  
Chemical Vapor ◽  
Hole Mobility ◽  
Significant Feature ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Silicon Growth ◽  
Silicon Germanium Alloys

ABSTRACTDichlorosilanc and germane were used to grow silicon-germanium alloys at temperatures as low as 550°C at atmospheric pressure. Germanium mole fractions as high as 44% were obtained and the layers exhibit smooth surface morphology. Silicon-gcrmanium/silicon multilayers with abrupt hctero-intcrfaccs have been achieved. Cross Section Transmission Electron Microscopy, (XTEM) and High Resolution X-Ray Diffraction, (HRXRD) characterization of the hetero-interface abruptness will be presented. Recent results on two-dimensional (2-D) hole mobility structures grown by this technique will also be reported. Selective growth of silicon-germanium on oxide patterned silicon wafers was also demonstrated. A significant feature of the selective deposition is the lack of faceting at the oxide sidcwall, which has been commonly observed in high temperature silicon growth.

Stress Induced During the Solid-phase Crystallization of Amorphous Silicon Deposited by LPCVD

1995 ◽  
Vol 403 ◽  
Author(s):  
T. Mohammed-Brahim ◽  
K. Kis-Sion ◽  
D. Briand ◽  
M. Sarret ◽  
F. Lebihan ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Solid Phase ◽  
Chemical Vapor ◽  
In Situ Monitoring ◽  
Crystallization Time ◽  
Solid Phase Crystallization ◽  
Pressure Chemical ◽  
Hall Effect Measurements ◽  
Deposition Techniques

AbstractThe Solid Phase Crystallization (SPC) of amorphous silicon films deposited by Low Pressure Chemical Vapor phase Deposition (LPCVD) using pure silane at 550'C was studied by in-situ monitoring the film conductance. The saturation of the conductance at the end of the crystallization process is found transient. The conductance decreases slowly after the onset of the saturation. This degradation is also observed from other analyses such as ellipsometry spectra, optical transmission and Arrhenius plots of the conductivity between 250 and 570K. Hall effect measurements show that the degradation is due to a decrease of the free carrier concentration n and not to a decrease of the mobility. This indicates a constant barrier height at the grain boundaries. The decrease of n is then due to a defect creation in the grain. Hence, whatever the substrate used, an optimum crystallization time exists. It depends on the amorphous quality film which is determined by the deposition techniques and conditions and on the crystallization parameters.

Polycrystalline Silicon Films Formed by Solid-Phase Crystallization of Amorphous Silicon: the Substrate Effects on Crystallization Kinetics and Mechanism

1996 ◽  
Vol 424 ◽  
Author(s):  
Y.-H. Song ◽  
S.-Y. Kang ◽  
K. I. Cho ◽  
H. J. Yoo ◽  
J. H. Kim ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Solid Phase Crystallization ◽  
Substrate Effects ◽  
Random Nucleation ◽  
Pressure Chemical ◽  
Si Films ◽  
Polycrystalline Silicon Films ◽  
Induced Crystallization

AbstractThe substrate effects on the solid-phase crystallization of amorphous silicon (a-Si) have been extensively investigated. The a-Si films were prepared on two kinds of substrates, a thermally oxidized Si wafer (SiO2/Si) and a quartz, by low-pressure chemical vapor deposition (LPCVD) using Si2H6 gas at 470 °C and annealed at 600 °C in an N2 ambient for crystallization. The analysis using XRD and Raman scattering shows that crystalline nuclei are faster formed on the SiO2/Si than on the quartz, and the time needed for the complete crystallization of a-Si films on the SiO2/Si is greatly reduced to 8 h from ˜15 h on the quartz. In this study, it was first observed that crystallization in the a-Si deposited on the SiO2/Si starts from the interface between the a-Si film and the thermal oxide of the substrate, called interface-induced crystallization, while random nucleation process dominates on the quartz. The very smooth surface of the SiO2/Si substrate is responsible for the observed interface-induced crystallization of a-Si films.

Grain size, Grain Uniformity, and (111) Texture Enhancement by Solid-phase Crystallization of F- and C-implanted SiGe Films

2000 ◽  
Vol 15 (7) ◽  
pp. 1630-1634 ◽  
Author(s):  
A. Rodríguez ◽  
J. Olivares ◽  
C. González ◽  
J. Sangrador ◽  
T. Rodríguez ◽  
...  
Keyword(s):  
Grain Size ◽  
Vapor Deposition ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Solid Phase Crystallization ◽  
Grain Sizes ◽  
Pressure Chemical ◽  
Film Microstructure ◽  
Si Films ◽  
Size Dispersion

The crystallization kinetics and film microstructure of poly-SiGe layers obtained by solid-phase crystallization of unimplanted and C- and F-implanted 100-nm-thick amorphous SiGe films deposited by low-pressure chemical vapor deposition on thermally oxidized Si wafers were studied. After crystallization, the F- and C-implanted SiGe films showed larger grain sizes, both in-plane and perpendicular to the surface of the sample, than the unimplanted SiGe films. Also, the (111) texture was strongly enhanced when compared to the unimplanted SiGe or Si films. The crystallized F-implanted SiGe samples showed the dendrite-shaped grains characteristic of solid-phase crystallized pure Si. The structure of the unimplanted SiGe and C-implanted SiGe samples consisted of a mixture of grains with well-defined contour and a small number of quasi-dendritic grains. These samples also showed a very low grain-size dispersion.

Effect of Ambient Atmosphere on Thin Film Reaction of Si3N4 with Ti

1989 ◽  
Vol 170 ◽  
Author(s):  
Seshu B. Desu ◽  
J. Ashley Taylor
Keyword(s):  
Layer Structure ◽  
Chemical Vapor ◽  
Product Formation ◽  
Ambient Atmosphere ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Rapid Thermal Annealer ◽  
The Stability ◽  
Increasing Temperature

AbstractThe reaction of sputtered deposited Ti films of 100 nm thick with low pressure chemical vapor deposited Si3N4 films (300 nm thick) was studied in N2 or Ar, in a rapid thermal annealer. Reactions are followed using x-ray diffraction, Auger electron spectroscopy, and transmission electron microscopy. In argon, the Si3N4 and Ti reaction at low temperatures led to the product formation of two layer structure (TiN/Ti5Si3), with some contaminant oxygen and nitrogen released from the reaction uniformly dissolved throughout the remaining unreacted Ti. At higher temperatures, a three layer structure, TiN/TixSiy/TiN, on unreacted Si3N4 was developed. With increasing temperature the value of x and y decreased from 5 to 0 and 3 to 1, respectively. Reactions in N2 ambient, irrespective of temperature, always produced the three layer structure, but the thickness of TixSiy layer was much smaller than that produced in argon ambient for the corresponding temperatures. The reaction mechanism can be explained in terms of relative diffusion coefficients and the stability of the interfaces.

Crystallization kinetics of yttrium aluminum garnet (Y3Al5O12)

2001 ◽  
Vol 16 (6) ◽  
pp. 1795-1805 ◽  
Author(s):  
Bradley R. Johnson ◽  
Waltraud M. Kriven
Keyword(s):  
Yttrium Aluminum Garnet ◽  
Three Dimensional ◽  
Constant Number ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Yttrium Aluminum ◽  
Temperature Transformation ◽  
Kinetics Of ◽  
Dimensional Crystal

The kinetics and pathways for crystallization of solid, amorphous, yttrium aluminum garnet (YAG) were studied using isothermal differential thermal analysis, x-ray diffraction, and transmission electron microscopy. The activation energy for crystallization was 437 KJ/mol and the measured Avrami exponent was 2.74, which corresponded to three-dimensional crystal growth with a constant number of nuclei. Time–temperature–transformation (T–T–T) curves were developed from the data to predict crystallization rates as a function of temperature. The crystallization pathway for YAG in this system is compared to others reported in the literature.

Heteroepitaxial Bi2Sr2CaCu2Ox Superconducting thin films Deposited on LaA1O3 by Solid Phase Epitaxy and OMCVD

1992 ◽  
Vol 275 ◽  
Author(s):  
J. Chen ◽  
H. A. Lu ◽  
F. DiMeo ◽  
B. W. Wessels ◽  
D. L. Schulz ◽  
...  
Keyword(s):  
Thin Films ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Superconducting Thin Films ◽  
Epitaxial Thin Films ◽  
Solid Phase Epitaxy ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Film Substrate

ABSTRACT-Heteroepitaxial superconducting Bi,Sr2CaCu2Ox (BSCCO 2212) thin films have been formed by solid phase epitaxy from amorphous films deposited on (100) LaA1O3 single crystal substrates by organometallic chemical vapor deposition. The epitaxial structure of the film is confirmed by x-ray diffraction including θ/2θ and Φ (in plane rotation) scans. Cross-sectional high resolution transmission electron microscopy indicates that the film-substrate interface is nearly atomically abrupt. Improvements in superconducting properties of the epitaxial thin films are noted in comparison to highly textured films deposited on MgO.

Characterization of polycrystalline silicon carbide films grown by atmospheric pressure chemical vapor deposition on polycrystalline silicon

1998 ◽  
Vol 13 (2) ◽  
pp. 406-412 ◽  
Author(s):  
Christian A. Zorman ◽  
Shuvo Roy ◽  
Chien-Hung Wu ◽  
Aaron J. Fleischman ◽  
Mehran Mehregany
Keyword(s):  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Deposition Process ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Polycrystalline Silicon Carbide ◽  
Pressure Chemical ◽  
Temperature Deposition ◽  
Sic Films

X-ray diffraction, transmission electron microscopy, and Rutherford backscattering spectroscopy were used to characterize the microstructure of polycrystalline SiC films grown on as-deposited and annealed polysilicon substrates. For both substrate types, the texture of the SiC films resembles the polysilicon at the onset of SiC growth. During the high temperature deposition process, the as-deposited polysilicon recrystallizes without influencing the crystallinity of the overlying SiC. An investigation of the SiC/polysilicon interface reveals that a heteroepitaxial relationship exists between polysilicon and SiC grains. From this study, a method to control the orientation of highly textured polycrystalline SiC films has been developed.

Formation of Heterogeneous Thickness Modulations During Epitaxial Growth of LPCVD-Si1−xGex/Si Quantum Well Structures

1992 ◽  
Vol 263 ◽  
Author(s):  
L. Vescan ◽  
W. Jäger ◽  
C. Dieker ◽  
K. Schmidt ◽  
A. Hartmann ◽  
...  
Keyword(s):  
Quantum Well ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Misfit Dislocations ◽  
Preferential Growth ◽  
Quantum Well Structures ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Dimensional Growth ◽  
Photoluminescence Studies

ABSTRACTTransmission electron microscopy and photoluminescence studies were performed to determine the critical thickness for generation of misfit dislocations in Sil-xGex layers grown by low pressure chemical vapor deposition. Above a certain Ge content the transition from two dimensional to three-dimensional growth occurs before generation of misfit dislocations. For instance, for x ∼0.3 and a substrate temperature around 700°C island formation was observed to start at 1.8 nm. The formation of islands is attributed to the preferential growth of SiGe in areas with less lattice strain. Islands were observed to broaden the exciton photoluminescence of the quantum well structures.

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