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 ◽  
...  

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.

1987 ◽  
Vol 107 ◽  
Author(s):  
D. Dutartre

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”.


1981 ◽  
Vol 4 ◽  
Author(s):  
B­Y. Tsaur ◽  
M. W. Gels ◽  
John C. C. Fan ◽  
D. J. Silversmith ◽  
R. W. Mountain

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.


1985 ◽  
Vol 53 ◽  
Author(s):  
D. Dutartre ◽  
M. Haond ◽  
D. Bensahel

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.


1984 ◽  
Vol 35 ◽  
Author(s):  
H. Baumgart ◽  
F. Phillipp

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.


1985 ◽  
Vol 53 ◽  
Author(s):  
M. W. Geis ◽  
C. K. Chen ◽  
Henry I. Smith ◽  
P. M. Nitishin ◽  
B-Y. Tsaur ◽  
...  

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.


1982 ◽  
Vol 13 ◽  
Author(s):  
B-Y. Tsaur ◽  
John C. C. Fan ◽  
M. W. Geis ◽  
R. L. Chapman ◽  
S. R. J. Brueck ◽  
...  

ABSTRACTDevice-quality Si films have been prepared by using graphite strip heaters for zone melting poly-Si films deposited on SiO2-coated substrates. The electrical characteristics of these films have been studied by the fabrication and evaluation of thin-film resistors, Mosfets and MOS capacitors. High yields of functional transistor arrays and ring oscillators with promising speed performance have been obtained for CMOS test circuit chips fabricated in recrystallized Si films on 2-inch-diameter Si wafers. Dualgate Mosfets with a three-dimensional structure have been fabricated by using the zone-melting recrystallization technique.


1992 ◽  
Vol 139 (9) ◽  
pp. 2687-2695 ◽  
Author(s):  
I. N. Miaoulis ◽  
P. Y. Wong ◽  
S. M. Yoon ◽  
R. D. Robinson ◽  
C. K. Hess

1982 ◽  
Vol 41 (9) ◽  
pp. 824-826 ◽  
Author(s):  
T. J. Stultz ◽  
J. F. Gibbons

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