Experimental Study of Precipitation Processes in Oxygen Implanted Silicon

1993 ◽  
Vol 316 ◽  
Author(s):  
R. Weber ◽  
R. Yankov ◽  
R. Müller ◽  
W. Skorupa ◽  
S. Reiss ◽  
...  

ABSTRACTSingle crystal (100) silicon substrates were implanted at 300 keV with substoichiometric oxygen doses ranging from 1 × 1016 to 1 × 1017 cm-2. Samples were annealed for 2 hours over the temperature range from 1100°C to 1250°C and were subsequently analysed by both cross sectional transmission electron microscopy (XTEM) and scanning electron microscopy (SEM). The nucleation and growth of oxide precipitates within the implanted layer was followed during annealing. The emphasis was placed upon studying the process of Ostwald ripening which is known to play an important role in the formation of the incipient buried layer. Besides, a clear trend of the SiO2 precipitates to arrange in well defined regions was revealed and this was attributed, as distinct from the earlier claims, to an inherent process of self organisation.

1993 ◽  
Vol 317 ◽  
Author(s):  
Bea CAO ◽  
N. David Theodore ◽  
Hank Shin ◽  
Peter Fejes ◽  
Les Hendrickson

ABSTRACTA variety of alloying elements are currently being investigated for their effects on the mechanical properties and reliability of thin aluminum films. In the present study, scanning electron microscopy and transmission electron microscopy are used to study the nucleation and growth of Al-1.5wt%Cu and Al-1.5wt% Cu-0.2wt% W films. Differences in Microstructure, nucleation and growth behavior are observed and are explained in terms of changes in surface energies and atomic Mobilities.


2006 ◽  
Vol 911 ◽  
Author(s):  
Hui Chen ◽  
Guan Wang ◽  
Yi Chen ◽  
Xiaoting Jia ◽  
Jie Bai ◽  
...  

AbstractCarrot-like defects in a 7&#61616; off-cut (from [0001] toward <1-210> direction) 4H-SiC wafer with a 36μm thick 4H-SiC epilayer have been investigated using Nomarski optical microscopy, synchrotron white beam x-ray topography (SWBXT), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). X-ray topographs confirm that threading screw dislocations are often associated with the carrots. Cross-sectional TEM observation confirms that a prismatic stacking fault exists below the carrot. This fault was found to show contrast in all observed diffraction geometries except for g=0004. A model for the mechanism of formation of this type of defect during epitaxial growth is proposed.


1996 ◽  
Vol 426 ◽  
Author(s):  
R. Hunger ◽  
R. Scheer ◽  
M. Alt ◽  
H. J. Lewerenz

AbstractCuInS2 films were grown by molecular beam epitaxy (MBE) on hydrogen terminated Si(111) substrates with 4° miscut. X-ray diffraction (XRD) texture analysis reveals that CuInS2 was grown heteroepitaxially with the epitaxial relationships CuInS2(112) II Si(111) and [111] II [111]. Moreover, a substantial amount of rotational twins is observed. The crystalline order is maintained across the interface as observed by cross-sectional transmission electron microscopy (XTEM). XRD and scanning electron microscopy (SEM) investigations show that nonstoichiometric preparation greatly influences the growth morphology and leads to the formation of secondary phases.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kun Yang ◽  
Jialu Xu ◽  
Ming Zhang ◽  
Daohui Lin

AbstractBiochar supported nanoscale zero-valent iron (NZVI/BC), prepared commonly by liquid reduction using sodium borohydride (NaBH4), exhibits better reduction performance for contaminants than bare NZVI. The better reducing ability was attributed to attachment of nanoscale zero-valent iron (NZVI) on biochar (BC) surface or into the interior pores of BC particles due to observations by scanning electron microscopy (SEM) and plan transmission electron microscopy (P-TEM) techniques in previous studies. In this study, cross-sectional TEM (C-TEM) technique was employed firstly to explore location of NZVI in NZVI/BC. It was observed that NZVI is isolated from BC particles, but not located on the surface or in the interior pores of BC particles. This observation was also supported by negligible adsorption and precipitation of Fe2+/Fe3+ and iron hydroxides on BC surface or into interior pores of BC particles respectively. Precipitation of Fe2+ and Fe3+, rather than adsorption, is responsible for the removal of Fe2+ and Fe3+ by BC. Moreover, precipitates of iron hydroxides cannot be reduced to NZVI by NaBH4. In addition to SEM or P-TEM, therefore, C-TEM is a potential technique to characterize the interior morphology of NZVI/BC for better understanding the improved reduction performance of contaminants by NZVI/BC than bare NZVI.


2006 ◽  
Vol 911 ◽  
Author(s):  
Masahide Gotoh ◽  
Takeshi Tawara ◽  
Shun-ichi Nakamura ◽  
Tae Tamori ◽  
Yoshiyuki Kuboki ◽  
...  

AbstractIn this study, we investigated surface features formed by molten KOH etching of (000-1) substrates and epilayers, using scanning electron microscopy (SEM) and cross-sectional transmission electron microscopy (TEM). We found the surface features formed on (000-1) are protrusions, in contrast to well-known dimples on (0001).


Author(s):  
P.J. Dailey

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).


Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).


Author(s):  
J. C. Russ ◽  
E. McNatt

In order to study the retention of copper in cirrhotic liver, rats were made cirrhotic by carbon tetrachloride inhalation twice weekly for three months and fed 0.2% copper acetate ad libidum in drinking water for one month. The liver tissue was fixed in osmium, sectioned approximately 2000 Å thick, and stained with lead citrate. The section was examined in a scanning electron microscope (JEOLCO JSM-2) in the transmission electron mode.Figure 1 shows a typical area that includes a red blood cell in a sinusoid, a disse, and a portion of the cytoplasm of a hepatocyte which contains several mitochondria, peribiliary dense bodies, glycogen granules, and endoplasmic reticulum.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


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