An amorphous-to-crystalline phase transition within thin silicon films grown through ultra-high-vacuum evaporation on fused quartz substrates

MRS Advances ◽  
2016 ◽  
Vol 1 (48) ◽  
pp. 3257-3262
Author(s):  
Farida Orapunt ◽  
Li-Lin Tay ◽  
David J. Lockwood ◽  
Jean-Marc Baribeau ◽  
Joanne C. Zwinkels ◽  
...  
Keyword(s):  
Phase Transition ◽  
Volume Fraction ◽  
High Vacuum ◽  
Optical Quality ◽  
Vacuum Evaporation ◽  
Silicon Films ◽  
Ultra High Vacuum ◽  
Fused Quartz ◽  
Thin Silicon ◽  
Quartz Substrates

ABSTRACTA number of thin silicon films are prepared through ultra-high-vacuum evaporation on optical quality fused quartz substrates with different growth temperatures. Through an analysis of grazing incidence X-ray diffraction results, a phase transition, from amorphous-to-crystalline, is found corresponding to increases in the growth temperature. The corresponding Raman spectra are also observed to change their form as the films go through this phase transition. Using a Raman peak decomposition process, this phase transition is then quantitatively characterized through the determination of the amount of intermediate-range order and the crystalline volume fraction for the various growth temperatures considered in this analysis. The possible device consequences of these results are then commented upon.

Amorphous Silicon Films and Superlattices Grown by Molecular Beam Epitaxy: An Optical Analysis

2002 ◽  
Vol 715 ◽  
Author(s):  
D. J. Lockwood ◽  
J.-M. Baribeau ◽  
M. Noël ◽  
J. C. Zwinkels ◽  
B. J. Fogal ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Amorphous Silicon ◽  
Molecular Beam ◽  
Crystalline Silicon ◽  
Quartz Substrate ◽  
High Vacuum ◽  
Impurity Content ◽  
Thin Layers ◽  
Silicon Films ◽  
Ultra High Vacuum

AbstractWe produce a novel form of amorphous silicon through ultra-high-vacuum molecular beam epitaxy. By depositing silicon atoms onto a fused quartz substrate at temperatures between 98 and 335°C, we obtain a silicon-based material that lacks the characteristic periodicity of crystalline silicon but nevertheless has 98% of its density. The impurity content of this material is studied through infrared and secondary ion mass spectroscopies. The primary impurity found is oxygen, with hydrogen and carbon atoms also being found at trace levels. The Raman spectra of the amorphous silicon films are measured and the results, as they relate to the presence of disorder, are interpreted. We also use this molecular beam epitaxy method to fabricate a number of amorphous silicon superlattices, comprised of thin layers of amorphous silicon separated with even thinner layers of SiO2. The optical properties of the films and superlattices are contrasted.

Orientation Dependent Epitaxial Growth of CeO2 Layers on Si Substrates

1991 ◽  
Vol 237 ◽  
Author(s):  
T. Inoue ◽  
T. Ohsuna ◽  
Y. Yamamoto ◽  
Y. Sakurai ◽  
L. Luo ◽  
...  
Keyword(s):  
Volume Fraction ◽  
High Vacuum ◽  
Amorphous Layer ◽  
Electron Beam Evaporation ◽  
Ultra High Vacuum ◽  
Lattice Image ◽  
Cross Sectional ◽  
Si Substrates ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron

ABSTRACTCerium dioxide (CeO2) layers epitaxially grown on (100), (111) and (110) silicon substrates by electron beam evaporation in an ultra-high vacuum were investigated. CeO2 layers on Si (111) substrates were proved to be epitaxially grown at the substrate temperature above 200°C, and had considerably good crystalline quality. On the other hand, CeO2 layers grown on Si (100) at 800°C consisted of more than 98% volume fraction of (110) component. Cross-sectional high resolution transmission electron microscopy and selected area electron diffraction verified clearly the above crystallography orientation and that the <100> direction in the CeO2(110) plane was parallel with the <110> direction in the Si (100) plane. The cross-sectional lattice image confirmed the existence of ∼ 6 nm-thick intermediate amorphous layer between the CeO2 layer and the Si substrate.

The Dependence of ETCH Pit Density on the Interfacial Oxygen Levels in Thin Silicon Layers Grown by Ultra High Vacuum Chemical Vapor Deposition

1992 ◽  
Vol 259 ◽  
Author(s):  
Manu J. Tejwani ◽  
Paul A. Ronsheim
Keyword(s):  
Power Law ◽  
High Vacuum ◽  
Chemical Vapor ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Etch Pit Density ◽  
Oxygen Levels ◽  
Etch Pit ◽  
Thin Silicon ◽  
Interfacial Oxygen

ABSTRACTFor low temperature silicon epitaxy it is not only important to have an oxygen free environment during growth but also an initial silicon surface free of trace concentrations of oxygen, carbon and other impurities. Variations in the pre-clean process (using the standard ex-situ aqueous hydrofluoric acid dip) used for ultra high vacuum chemical vapor depostion (UHVCVD) of silicon, result in interfacial oxygen levels ranging from 2 × 1012atoms/cm2 to 1014atoms/cm2 as measured by secondary ion ion mass spectroscopy (SIMS). Using a dilute Schimmel etch we have delineated the dislocations in the thin silicon epitaxial layers grown by UHVCVD. Correlation of the etch pit density to the interfacial oxygen levels suggests a power law dependence. Plausibility arguments are presented to explain this power law dependence.

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