Gettering layer formation in low-dose SIMOX wafers

2002 ◽  
Author(s):  
J. Jablonski ◽  
M. Saito ◽  
M. Imai ◽  
S. Nakashima
Keyword(s):  
Low Dose ◽  
Layer Formation

Effect of Oxygen Implantation Conditions on Buried Si02 Layer Formation using a Multiple Step Process

1989 ◽  
Vol 157 ◽  
Author(s):  
F. Namavar ◽  
E. Cortesi ◽  
R.F. Pinizzotto ◽  
H. Yang
Keyword(s):  
Low Dose ◽  
Layer Formation ◽  
Reduced Dose ◽  
Oxygen Implantation ◽  
Implantation Temperature ◽  
Implantation Process ◽  
Effect Of Oxygen ◽  
Radiation Hard ◽  
Dose Step ◽  
Multiple Step

ABSTRACTWe have studied the effect of implantation temperature, dose step, and total dose on the buried Si02 layer formed with a multiple low dose oxygen implantation process. Furthermore, we have produced a continuous, high quality buried SiO2 layer about 1500 Å thick with a dose of only 7 × 1017 0+/cm2 at 160 keV. The thin SiO2 layer is important not only because of the possible economic advantages of reduced dose, but also because a thinner oxide layer is more radiation hard.

Defect Dynamics in Simox Structures as a Function of the Annealing Parameters

2000 ◽  
Vol 6 (S2) ◽  
pp. 1086-1087
Author(s):  
Yan Tan ◽  
Benedict Johnson ◽  
Supapan Seraphin ◽  
Maria J. Anc
Keyword(s):  
High Speed ◽  
Low Dose ◽  
Ostwald Ripening ◽  
Layer Structure ◽  
High Dose ◽  
Layer Formation ◽  
Oxygen Ion ◽  
The Cost ◽  
Oxygen Ion Implantation ◽  
Post Implantation

Advanced semiconductor devices on the SIMOX (Separation by IMplanted OXygen) substrate have many advantages including high-speed, large packing density and low power consumption. SIMOX consists of a layer structure generated by oxygen ion implantation into silicon wafers. The implantation process introduces a high density of defects that can be reduced by post-implantation annealing. Decreasing the oxygen dose not only reduces the cost but also decreases the damage to the top Si layers. Low-dose implantation results in thinner buried oxide (BOX) layer, in contrast to traditional high-dose SIMOX. The BOX layer formation mechanism is different for low-dose SIMOX from that of high-dose. For a high-dose SIMOX, the BOX layer is already formed by implantation. However, for a low-dose, a number of oxide precipitates are formed during implantation. The larger precipitates grow at the expense of smaller ones until they coalesce to the BOX layer during annealing. This step is known as Ostwald ripening, which is responsible for the thin BOX formation.

Helium-induced porous layer formation in Silicon.

1987 ◽  
Vol 107 ◽  
Author(s):  
A. Van Veen ◽  
C.C. Griffioen ◽  
J.H. Evans
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ambient Temperature ◽  
Porous Layer ◽  
Low Dose ◽  
Layer Formation ◽  
Helium Bubbles ◽  
Transmission Electron ◽  
Helium Implantation ◽  
The Stability

AbstractThe annealing behaviour of helium bubbles formed by ambient temperature 10 keV helium implantation into silicon has been studied using transmission electron microscopy (TEM) and helium desorption spectroscopy (HDS). Although the TEM results indicated conventional bubble annealing processes due to bubble migration and coalescence, the HDS data demonstrated that helium can permeate out of bubbles in silicon around 1000K to leave behind empty cavities, thus giving a porous layer coincident with the original helium implant profile.The addition of a low dose of implanted oxygen to the silicon-helium samples has been shown to strongly improve the stability of the porous layer, at least up to 1300K.

Stimulated Creation of the SOI Structures with Si Nano-Clustersw by Low–Dose SIMOX Technology

2011 ◽  
Vol 178-179 ◽  
pp. 17-24 ◽  
Author(s):  
V.G. Litovchenko ◽  
Boris Romanyuk ◽  
Viktor Melnik ◽  
Vasyl Klad’ko ◽  
Valentin Popov ◽  
...  
Keyword(s):  
Carbon Concentration ◽  
Oxygen Diffusion ◽  
Low Dose ◽  
Carbon Ions ◽  
Layer Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Ions ◽  
Buried Layer ◽  
Diffraction Patterns

The peculiarities of a buried layer formation obtained by a co-implantation of O2 ions with the energy of 130 keV and carbon ions within the energy range of 30-50 keV have been investigated. The corresponding ion doses for carbon and oxygen ions were equal to 2∙1016 cm-2 and 1.8∙1017 cm-2, respectively. It has been observed that annealing at 1150°C results in enhanced oxygen diffusion towards the region with a maximum carbon concentration. Analysis of x-ray diffraction patterns and TEM images confirm formation of Si nanoclusters in the SiO2 buried layer. The intensive luminescence with the maximum at 600 nm has been observed in the synthesized structures.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

Characterization of microtubules by dark-field STEM and replication

1991 ◽  
Vol 49 ◽  
pp. 152-153
Author(s):  
S.B. Andrews ◽  
R.D. Leapman ◽  
P.E. Gallant ◽  
T.S. Reese
Keyword(s):  
Protein Interactions ◽  
Low Dose ◽  
Unit Length ◽  
Dark Field ◽  
Carbon Films ◽  
Microtubule Associated Proteins ◽  
Molecular Weights ◽  
Freeze Dried ◽  
Protein Motors ◽  
Associated Proteins

As part of a study on protein interactions involved in microtubule (MT)-based transport, we used the VG HB501 field-emission STEM to obtain low-dose dark-field mass maps of isolated, taxol-stabilized MTs and correlated these micrographs with detailed stereo images from replicas of the same MTs. This approach promises to be useful for determining how protein motors interact with MTs. MTs prepared from bovine and squid brain tubulin were purified and free from microtubule-associated proteins (MAPs). These MTs (0.1-1 mg/ml tubulin) were adsorbed to 3-nm evaporated carbon films supported over Formvar nets on 600-m copper grids. Following adsorption, the grids were washed twice in buffer and then in either distilled water or in isotonic or hypotonic ammonium acetate, blotted, and plunge-frozen in ethane/propane cryogen (ca. -185 C). After cryotransfer into the STEM, specimens were freeze-dried and recooled to ca.-160 C for low-dose (<3000 e/nm2) dark-field mapping. The molecular weights per unit length of MT were determined relative to tobacco mosaic virus standards from elastic scattering intensities. Parallel grids were freeze-dried and rotary shadowed with Pt/C at 14°.

Structural analysis of the surface-layer protein of spirillum serpens by high-resolution electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 738-739
Author(s):  
W. H. Wu ◽  
R. M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Analysis ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Surface Layer Protein ◽  
Morphological Unit ◽  
Resolution Electron

Spirillum serpens possesses a surface layer protein which exhibits a regular hexagonal packing of the morphological subunits. A morphological model of the structure of the protein has been proposed at a resolution of about 25 Å, in which the morphological unit might be described as having the appearance of a flared-out, hollow cylinder with six ÅspokesÅ at the flared end. In order to understand the detailed association of the macromolecules, it is necessary to do a high resolution structural analysis. Large, single layered arrays of the surface layer protein have been obtained for this purpose by means of extensive heating in high CaCl2, a procedure derived from that of Buckmire and Murray. Low dose, low temperature electron microscopy has been applied to the large arrays.As a first step, the samples were negatively stained with neutralized phosphotungstic acid, and the specimens were imaged at 40,000 magnification by use of a high resolution cold stage on a JE0L 100B. Low dose images were recorded with exposures of 7-9 electrons/Å2. The micrographs obtained (Fig. 1) were examined by use of optical diffraction (Fig. 2) to tell what areas were especially well ordered.

The Response of Testis Cells to Low Dose X-Irradiation

1981 ◽  
Vol 39 ◽  
pp. 542-543
Author(s):  
D. E. Philpott ◽  
W. Sapp ◽  
C. Williams ◽  
Joann Stevenson ◽  
S. Black
Keyword(s):  
Electron Microscopy ◽  
Stem Cell ◽  
Light Microscopy ◽  
Dose Level ◽  
Cross Sections ◽  
Low Dose ◽  
Light And Electron Microscopy ◽  
Cellular Responses ◽  
Post Irradiation ◽  
X Irradiation

The response of spermatogonial cells to X-irradiation is well documented. It has been shown that there is a radiation resistent stem cell (As) which, after irradiation, replenishes the seminiferous epithelium. Most investigations in this area have dealt with radiation dosages of 100R or more. This study was undertaken to observe cellular responses at doses less than 100R of X-irradiation utilizing a system in which the tissue can be used for light and electron microscopy.Brown B6D2F1 mice aged 16 weeks were exposed to X-irradiation (225KeV; 15mA; filter 0.35 Cu; 50-60 R/min). Four mice were irradiated at each dose level between 1 and 100 rads. Testes were removed 3 days post-irradiation, fixed, and embedded. Sections were cut at 2 microns for light microscopy. After staining, surviving spermatogonia were identified and counted in tubule cross sections. The surviving fraction of spermatogonia compared to control, S/S0, was plotted against dose to give the curve shown in Fig. 1.

Search mode for rapid detection of virus particles

1991 ◽  
Vol 49 ◽  
pp. 286-287
Author(s):  
O. E. Bradfute
Keyword(s):  
Electron Microscopy ◽  
Rapid Detection ◽  
Plant Virus ◽  
Low Dose ◽  
Search Mode ◽  
Virus Diseases ◽  
Virus Particles ◽  
Focus Image ◽  
Time Required ◽  
Rapid Switching

Electron microscopy is frequently used in preliminary diagnosis of plant virus diseases by surveying negatively stained preparations of crude extracts of leaf samples. A major limitation of this method is the time required to survey grids when the concentration of virus particles (VPs) is low. A rapid survey of grids for VPs is reported here; the method employs a low magnification, out-of-focus Search Mode similar to that used for low dose electron microscopy of radiation sensitive specimens. A higher magnification, in-focus Confirm Mode is used to photograph or confirm the detection of VPs. Setting up the Search Mode by obtaining an out-of-focus image of the specimen in diffraction (K. H. Downing and W. Chiu, private communications) and pre-aligning the image in Search Mode with the image in Confirm Mode facilitates rapid switching between Modes.

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