Microscopy of Thin Si Films During Lamp Zone Melting

1985 ◽  
Vol 53 ◽  
Author(s):  
D. Dutartre ◽  
M. Haond ◽  
D. Bensahel
Keyword(s):  
Zone Melting ◽  
Silicon On Insulator ◽  
Spatial Modulation ◽  
Freezing Front ◽  
Melting Front ◽  
Scan Speed ◽  
Entrainment Effect ◽  
Si Films ◽  
Melting And Solidification

ABSTRACTThe melting and solidification fronts of thin Silicon On Insulator (SOI) films have been observed in-situ. The melting front does not advance continuously but by bursts. This so called “explosive melting” allows to explain the appearance of defects (such as voids and surface roughness) observed in the recrystallized film. The freezing front is observed in the case where a pattern for the entrainment of the defects has been etched in the underlying oxide: we show that the entrainment effect is due to the spatial modulation of the solidification front by the structure. Furthermore, the scan speed influences the morphology of the liquid/solid interface and the defect entrainment efficiency.

Melting and Solidification Dynamics in Zone Melting of Si Films.

1987 ◽  
Vol 107 ◽  
Author(s):  
D. Dutartre
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Zone Melting ◽  
Silicon On Insulator ◽  
Experimental Conditions ◽  
Melting Front ◽  
Physical Mechanisms ◽  
Si Films ◽  
Melting And Solidification

AbstractWe discuss the physics involved in the melting and solidification of Silicon On Insulator thin films (SOI) using lamp or graphite strip heaters. The melting front, called “explosive melting”, controls to a large part the final morphological quality of the SOI film. It exhibits instabilities which can (i) nucleate the dewetting of the film, (ii) cause voids, and (iii) produce a poor surface morphology. The morphologies of the solidification fronts are analyzed. We show that, depending on the experimental conditions, different physical mechanisms are responsible for the front breakdown. Thus we propose that the variety of front morphologies results from the variety of the mechanisms involved, and of their combinations with the “faceting effects”.

Growth -Front Modulation in Lamp Zone Melting of Si on SiO2

1986 ◽  
Vol 74 ◽  
Author(s):  
D. Dutartre ◽  
D. Bensahel ◽  
M. Haond
Keyword(s):  
Solidification Front ◽  
Growth Front ◽  
Zone Melting ◽  
Silicon On Insulator ◽  
Polysilicon Film ◽  
Defect Localization ◽  
In Situ Observations ◽  
Periodical Variation

AbstractWe present 3 techniques of defect localization we have studied in order to produce Silicon On Insulator films obtained by Lamp Zone Melting. They consist in a periodical variation of the thickness of either the oxide cap, or the polysilicon film, or the underlying oxide layer. We compare the crystallographic quality of the resulting films and in-situ observations of the solidification front for each structure.

Silicon-On-Insulator Mosfets Fabricated in Zone-Melting-Recrystallized Poly-Si Films on SiO2

1981 ◽  
Vol 4 ◽  
Author(s):  
B­Y. Tsaur ◽  
M. W. Gels ◽  
John C. C. Fan ◽  
D. J. Silversmith ◽  
R. W. Mountain
Keyword(s):  
Carrier Mobility ◽  
High Surface ◽  
Zone Melting ◽  
Silicon On Insulator ◽  
Surface Electron ◽  
Leakage Currents ◽  
Si Substrates ◽  
Enhancement Mode ◽  
Low Leakage ◽  
Si Films

ABSTRACTN- and p-channel enhancement-mode MOSFETs have been fabricated in Si films prepared by zone-melting recrystallization of poly-Si deposited on SiO2-coated Si substrates. The transistors exhibit high surface mobilities, in the range of 560–620 cm2/V−s for electrons and 200–240 cm2/V−s for holes, and low leakage currents of the order of 0.1 pA/μm (channel width). Uniform device performance with a yield exceeding 90% has been measured in tests of more than 100 devices. The interface between the Si film and the SiO2 layer on the substrate is characterized by an oxide charge density of 1–2 × 1011 cm−2 and a high surface carrier mobility. N-channel MOSFETs fabricated inSi films recrystallized on SiO2-coated fused quartz subtrates exhibit surface electron mobilities substantially higher than those of single-crystal Si devices because the films are under a large tensile stress.

Capping Techniques for Zone-Melting-Recrystallized Si-On-Insulator Films

1985 ◽  
Vol 53 ◽  
Author(s):  
C.K. Chen ◽  
L. Pfeiffer ◽  
K.W. West ◽  
M.W. Gels ◽  
S. Darack ◽  
...  
Keyword(s):  
Crystallographic Texture ◽  
Auger Spectroscopy ◽  
Zone Melting ◽  
Silicon On Insulator ◽  
Capping Layer ◽  
Spectroscopy Studies ◽  
Si Films ◽  
Film Annealing

ABSTRACTTo prepare silicon-on-insulator (SOI) films by graphite-strip-heater zone-melting recrystallization (ZMR), a capping technique must be used to insure wetting by the molten Si zone. We have demonstrated two new capping techniques that result in reproducible wetting without degrading the crystallographic texture of the recrystallized film: annealing SiO2- capped Si films in NH3 and depositing two SiNx layers with carefully controlled compositions on the SiO2 capping layer. Wetting is promoted by the incorporation of trace amounts of nitrogen at the Si-SiO2 interface. Both N implantation experiments and Auger spectroscopy studies establish that the presence of less than a monolayer of nitrogen at this interface is sufficient to insure wetting.

Liquid-Solid Interface Morphologies and Defect Structures in Zone-Melting-Recrystallized Silicon-On-Insulator Films

1987 ◽  
Vol 107 ◽  
Author(s):  
J. S. Im ◽  
C. K. Chen ◽  
C. V. Thompson ◽  
M. W. Geis ◽  
H. Tomita
Keyword(s):  
Zone Melting ◽  
Silicon On Insulator ◽  
Radiative Heating ◽  
Interfacial Region ◽  
Defect Structures ◽  
Interface Morphology ◽  
Experimental Conditions ◽  
Solid Interface ◽  
Free Films

AbstractIn-situ optical microscopy has been used to observe liquid-solid interface morphologies during zone-melting recrystallization of silicon-on-insulator films. These morphologies have been correlated with the defect morphologies of the recrystallized films. Stable cellular solidification fronts, which are obtained at low zone velocities if the radiation intensity gradient in the interfacial region is small, yield subboundary free films. We suggest that under these experimental conditions the interface morphology is primarily the result of radiative heating rather than constitutional supercooling.

High-Voltage Electron Microscopy Investigation of Subgrain Boundaries in Recrystallized Silicon-On-Insulator Structures

1984 ◽  
Vol 35 ◽  
Author(s):  
H. Baumgart ◽  
F. Phillipp
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Zone Melting ◽  
Silicon On Insulator ◽  
Stress Concentrations ◽  
Growth Interface ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Si Films

ABSTRACTThe microstructure of high-quality recrystallized Si films on SiO2 substrates produced by CO2 laser induced zone-melting has been investigated by high voltage electron microscopy (HVEM). Subgrain boundaries represent the major defects in these recrystallized films. The origin of the subboundaries has been traced to periodic internal stress concentrations occurring at the faceted growth interface. These highly localized stresses cause plastic deformation of the growing single crystal film by nucleation of an array of slip dislocations. The mechanism responsible for the formation of subgrain boundaries has been revealed to be polygonization, where thermally activated dislocations rearrange themselves into the lower energy configuration of the low angle grain boundary.

Elimination of Subboundaries from Zone-Melting-Recrystallized Silicon-On-Insulator Films

1985 ◽  
Vol 53 ◽  
Author(s):  
M. W. Geis ◽  
C. K. Chen ◽  
Henry I. Smith ◽  
P. M. Nitishin ◽  
B-Y. Tsaur ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Thermal Gradient ◽  
Zone Melting ◽  
Silicon On Insulator ◽  
Crystalline Defects ◽  
Si Films

ABSTRACTSince the introduction of zone-melting recrystallization (ZMR)for silicon-on-insulator (SOI) films, subboundaries (low-angle grain boundaries) have been the major crystalline defects in recrystallized films. By using an improved ZMR procedure, subboundaries have been eliminated over large areas. The improvements include the use of 1-µm-thick polycrystalline-Si films deposited on 2-µm-thick thermal SiO2 film (instead of 0.5-µm-thick Si and SiO2 films), a new encapsulation technique, and improved control of the thermal gradient during ZMR. Recrystallized SOI films without subboundaries contain isolated dislocations with densities <2 × 106 cm−2.

In situ synthesis of composite MTiO3–Al2O3 coatings via laser zone melting

2007 ◽  
Vol 9 (5) ◽  
pp. 404-409 ◽  
Author(s):  
V.V. Lennikov ◽  
J.M. Pedra ◽  
J.J. Gómez ◽  
G.F. de la Fuente ◽  
J.B. Carda
Keyword(s):  
Zone Melting ◽  
In Situ Synthesis
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