Improvements in Zone Melt Recrystallized Soi Layers by the Use of Selective Epitaxial Growth in the Seed Windows.

1987 ◽  
Vol 107 ◽  
Author(s):  
D.A. Williams ◽  
R.A. McMahon ◽  
H. Ahmed ◽  
L. Karapiperis ◽  
G. Garry ◽  
...  

AbstractThe effect of selective epitaxial growth (SEG) of silicon in the seed windows of silicon on insulator structures prior to recrystallization has been investigated. Subsequent zone melt recrystallization of these structures was performed in a dual electron beam system, and it was found that the full planarisation of the deposited silicon layer results in uniform film thickness after recrystallization. Cross sectional scanning and transmission electron microscopy, optical microscopy after defect etching, and bevelling are used to analyse the material. The SEG method improves the uniformity of the film for device island etching, and so is useful for all silicon on insulator applications, although the one of most interest for these investigations is the production of three dimensional circuitry. This is achieved by stacking layers of devices, and so planarity is particularly important.

1990 ◽  
Vol 188 ◽  
Author(s):  
Ingrid De Wolf ◽  
Jan Vanhellemont ◽  
Herman E. Maes

ABSTRACTMicro Raman spectroscopy (RS) is used to study the crystalline quality and the stresses in the thin superficial silicon layer of Silicon-On-Insulator (SO) materials. Results are presented for SIMOX (Separation by IMplanted OXygen) and ZMR (Zone Melt Recrystallized) substrates. Both as implanted and annealed SIMOX structures are investigated. The results from the as implanted structures are correlated with spectroscopic ellipsometry (SE) and cross-section transmission electron microscopy (TEM) analyses on the same material. Residual stress in ZMR substrates is studied in low- and high temperature gradient regions.


Author(s):  
Z. S. H. Weng-Sieh ◽  
J. C. Lou ◽  
W. G. Oldham ◽  
R. Gronsky

In the interest of obtaining increased integrated circuit device density, a relatively new technology known as selective epitaxial growth (SEG) of silicon is being explored, especially for improved isolation of devices including possible three dimensional (vertical) integration. This technology involves the deposition and selective nucleation and growth of silicon from the vapor phase, seeded by the silicon substrate. The process is “selective” because nucleation and growth occurs on the silicon substrate but is prohibited on the oxide. The epitaxial silicon proceeds to grow upward and laterally over the oxide.Silicon deposition was performed in a horizontal hot-walled low pressure chemical vapor deposition (LPCVD) reactor. A dry thermal oxide was grown on the substrates, patterned, and etched to create seed windows. A 900 °C prebake was performed at a pressure of 6 torr in a hydrogen ambient for a period of 15 minutes, with in some cases, a small concentration (approximately 0.025%) of dichlorosilane (DCS) gas, and deposition was performed at 850 °C through the decomposition of DCS gas: SiH2Cl2 -> Si(s)+ 2HCl(g).


2007 ◽  
Vol 994 ◽  
Author(s):  
Douglas C. Thompson ◽  
T. L. Alford ◽  
J. W. Mayer ◽  
T. Hochbauer ◽  
J. K. Lee ◽  
...  

AbstractMicrowave heating is used to initiate the ion-cut process for transfer of coherent silicon-layers onto insulator substrates. Hydrogen and boron co-implanted silicon was bonded to an insulative substrate before processing inside a 2.45 GHz, 1300 W cavity applicator microwave system. Sample temperatures measured using a pyrometer were comparable to previous ion – cut studies. Selected samples were further annealed to repair any damage created in the ion implant process. Rutherford backscattering spectrometry and selective area electron diffraction patterns show high crystallinity in transferred layers. RUMP simulation of backscattering spectra and cross-sectional transmission electron microscopy demonstrate that thicknesses of the transferred layers are comparable to previous ion-cut exfoliation techniques. Surface quality as characterized by an atomic force microscope compares well with previous ion-cut studies. Hall measurements were used to characterize electrical properties of transferred layers. The mobility and carrier density of microwave activated ion – cut silicon on insulator processed samples compares well with previous annealing techniques.


Author(s):  
H. Takaoka ◽  
M. Tomita ◽  
T. Hayashi

High resolution transmission electron microscopy (HRTEM) is the effective technique for characterization of detailed structure of semiconductor materials. Oxygen is one of the important impurities in semiconductors. Detailed structure of highly oxygen doped silicon has not clearly investigated yet. This report describes detailed structure of highly oxygen doped silicon observed by HRTEM. Both samples prepared by Molecular beam epitaxy (MBE) and ion implantation were observed to investigate effects of oxygen concentration and doping methods to the crystal structure.The observed oxygen doped samples were prepared by MBE method in oxygen environment on (111) substrates. Oxygen concentration was about 1021 atoms/cm3. Another sample was silicon of (100) orientation implanted with oxygen ions at an energy of 180 keV. Oxygen concentration of this sample was about 1020 atoms/cm3 Cross-sectional specimens of (011) orientation were prepared by argon ion thinning and were observed by TEM at an accelerating voltage of 400 kV.


2017 ◽  
Vol 16 (4) ◽  
pp. 302-307
Author(s):  
Tom Schlösser ◽  
Rob Brink ◽  
René Castelein

ABSTRACT Despite many years of dedicated research into the etiopathogenesis of adolescent idiopathic scoliosis, there is still no single distinct cause for this puzzling condition. In this overview, we attempt to link knowledge on the complex three-dimensional pathoanatomy of AIS, based on our ongoing research in this field, with etiopathogenic questions. Evidence from multiple recent cross-sectional imaging studies is provided that supports the hypothesis that AIS has an intrinsic biomechanical basis: an imbalance between the biomechanical loading of the upright human spine due to its unique sagittal configuration on the one hand, and the body’s compensating mechanisms on the other. The question that remains in the etiology of AIS, and the focus of our ongoing research, is to determine what causes or induces this imbalance.


1987 ◽  
Vol 1 (2) ◽  
pp. 322-329 ◽  
Author(s):  
H. Warshawsky

The purpose of this paper is to review evidence which casts doubt on the interpretation universally applied to hexagonal images seen in sectioned enamel. The evidence is based on two possible models to explain the hexagonal profiles seen in mammalian enamel with transmission electron microscopy. The "hexagonal ribbon" model proposes that hexagonal profiles are true cross-sections of elongated hexagonal ribbons. The "rectangular ribbon" model proposes that hexagonal profiles are caused by three-dimensional segments that are parallelepipeds contained in the Epon section. Since shadow projections of such rectangular segments give angles that are inconsistent with the hexagonal unit cell, a model based on ribbons with rhomboidal cut ends and angles of 60 and 120° is proposed. The "rhomboidal ribbon" model projects shadows with angles that are predicted by the unit cell. It is suggested that segments of such crystallites in section project as opaque hexagons on the imaging plane in routine transmission electron microscopy. Morphological observations on crystallites in sections - together with predictions from the hexagonal, rectangular, and rhomboidal ribbon models - indicate that crystallites in rat incisor enamel are flat ribbons with rhomboidal cross-sectional shape. Hexagonal images in electron micrographs of thin-sectioned enamel can result from rhomboidal-ended, parallelepiped-shaped segments of these crystallites projected and viewed as two-dimensional shadows.


1999 ◽  
Vol 20 (5) ◽  
pp. 194-196 ◽  
Author(s):  
Sangwoo Pae ◽  
Taichi Su ◽  
J.P. Denton ◽  
G.W. Neudeck

Author(s):  
Rashmi Raghu ◽  
Charles A. Taylor

The one-dimensional (1-D) equations of blood flow consist of the conservation of mass equation, balance of momentum equation and a wall constitutive equation with arterial flow rate, cross-sectional area and pressure as the variables. 1-D models of blood flow enable the solution of large networks of blood vessels including wall deformability. Their level of detail is appropriate for applications such as modeling flow and pressure waves in surgical planning and their computational cost is low compared to three-dimensional simulations.


Sign in / Sign up

Export Citation Format

Share Document