Characterization and Evolution of Microstructures Formed by High Dose Oxygen Implantation of silicont

1986 ◽  
Vol 74 ◽  
Author(s):  
M. K. El-Ghor ◽  
S. J. Pennycook ◽  
T. P. Sjoreen ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Silicon Oxide ◽  
Microstructural Analysis ◽  
High Dose ◽  
Oxide Interface ◽  
Transmission Electron ◽  
Spherical Cavities ◽  
High Doses ◽  
Electron Energy Loss ◽  
Post Implantation

AbstractHigh doses of oxygen were implanted in silicon to produce stoichiometric buried oxide structures. Microstructural analysis was performed using transmission electron microscopy, electron energy loss spectroscopy, and Rutherford backscattering/channeling techniques. Cavities were observed in the top silicon layers of the as-implanted samples in two forms: spherical cavities (30–300 Å in diameter) in the first 1000 Å below the surface, followed by a 500 Å wide lamellar array of elongated cavities. A post implantation annealing was carried out at temperatures between 1150°C and 1250°C for 3 h during which the cavities became faceted and a denuded zone of 400 Å was formed. However, with a 1300°C anneal the cavities disappeared and the density of the two prominent types of defects, namely precipitates (mostly amorphous, but occasionally crystalline) and dislocations, decreased significantly. The silicon-oxide interface became increasingly planar. Possible mechanisms of annealing of the cavities, the precipitates, and the associated planarization of the interface are proposed.

Formation of Nanovoids and Nanocolumns in High Dose Hydrogen Implanted ZnO Bulk Crystals

2006 ◽  
Vol 957 ◽  
Author(s):  
Rajendra Singh ◽  
R. Scholz ◽  
U. Gösele ◽  
S. H. Christiansen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Dose ◽  
Hydrogen Ions ◽  
Bulk Crystals ◽  
Cross Sectional ◽  
Projected Range ◽  
Transmission Electron ◽  
Wafer Surfaces ◽  
Post Implantation

ABSTRACTZnO(0001) bulk crystals were implanted with 100 keV H2+ ions with various doses in the range of 5×1016 to 3×1017 cm-2. The ZnO crystals implanted up to a dose of 2.2×1017 cm-2 did not show any surface exfoliation, even after post-implantation annealing at temperatures up to 800°C for 1 h while those crystals implanted with a dose of 2.8×1017 cm-2 or higher exhibited exfoliated surfaces already in the as-implanted state. In a narrow dose window in between, controlled exfoliation could be obtained upon post-implantation annealing only. Cross-sectional transmission electron microscopy (XTEM) of the implanted ZnO samples showed that a large number of nanovoids were formed within the implantation-induced damage band. These nanovoids served as precursors for the formation of microcracks leading to the exfoliation of ZnO wafer surfaces. In addition to the nanovoids, elongated nanocolumns perpendicular to the ZnO wafer surfaces were also observed. These nanocolumns showed diameters of up to 10 nm and lengths of up to 500 nm. The nanocolumns were found in the ZnO wafer even well beyond the projected range of hydrogen ions.

Investigation of instinctive defects in nitrogen enrich lanthanum silicon oxynitride glasses

2020 ◽  
Author(s):  
Sharafat Ali ◽  
Abbas Saeed Hakeem ◽  
Thomas Höche ◽  
Qasem Ahmed Drmosh ◽  
Amir Azam Khan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silicon Oxide ◽  
Glass Network ◽  
Nitrogen Atmosphere ◽  
Silicon Oxynitride ◽  
Subsequent Reaction ◽  
Preparation Temperature ◽  
Glass Forming ◽  
Transmission Electron ◽  
Electron Energy Loss

Abstract Oxynitride glasses are not yet commercialised primarily due to the impurities present in the network of these glasses. In this work, silicon and silicide defects in nitrogen-rich La-Si-O-N glasses were investigated. Glasses were prepared by heating powder mixture of La metal, Si 3 N 4 , and SiO 2 in a nitrogen atmosphere at 1650-1800°C. The obtained glasses containing an unprecedented amount of N content of up to 68 e/o and La up to 62 e/o in the glass network which reveals a broader glass-forming region in the system than previously reported. The microstructure and impurities in the glasses were examined by optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) in conjunction with electron energy-loss spectroscopy (EELS). Analyses showed that the glasses contain a small amount of spherical La silicides particles, mostly amorphous or poorly crystalline, and having sizes typically ranging from 1 µm and less. The amount of silicide was estimated to be less than 2 vol.%. There was no systematic relation between silicide formation and glass composition or preparation temperature, but it was found that particle size decrease with increasing holding time. The limited transparency of high N-containing glasses is expected to have attribution of elemental Si and microscopy analyses, and Raman spectroscopy ascertained silicide particles. Furthermore, a metallic silicide formed by the decomposition of silicon oxide and silicon nitride, then the subsequent reaction of Si and La.

Applications of High Spatial Resolution Analytical Electron Microscopy to the Process Development of Silicon Devices

1997 ◽  
Vol 3 (S2) ◽  
pp. 471-472
Author(s):  
B. Ameirhekmat ◽  
L.Y. Tsung ◽  
H.L. Tsai ◽  
J.P. Lu
Keyword(s):  
Electron Microscopy ◽  
Thin Layer ◽  
Silicon Oxide ◽  
Process Development ◽  
Analytical Electron Microscopy ◽  
Chemical Information ◽  
Silicon Devices ◽  
Transmission Electron ◽  
Incomplete Removal ◽  
Electron Energy Loss

Analytical transmission electron microscopy (AEM) equipped with a field emission gun has made it possible to analyze chemical information at local spots or interfaces with a very small electron probe. This technique has been applied to assist in process development and addressing certain reliability issues in silicon devices.Figure 1 shows an example of applications of AEM to a 0.5 μm transistor. An oxide bump is found to be located in the middle of a transistor. A very thin layer (20 Å) is on the top of the oxide bump. Using EDS, the bump is determined to be a silicon oxide, but EDS failed to analyze the thin layer. Electron energy loss spectroscopy detects nitrogen in this residual layer (Fig. la), suggesting that the residue is a thin nitride. This residual nitride is caused by the incomplete removal of the nitride mask after field oxidation. This nitride residue blocks the subsequent removal of the buffer oxide between the nitride mask and the substrate.

Microstructural Analysis of SiO2-Al2O3 Glasses

1982 ◽  
Vol 40 ◽  
pp. 562-563
Author(s):  
C. M. Jantzen ◽  
D. G. Howitt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Microstructural Analysis ◽  
Liquid Immiscibility ◽  
Metastable Region ◽  
Transmission Electron ◽  
Liquidus Temperatures

The mullite-SiO2 liquidus has been extensively studied, and it has been shown that the flattening of the liquidus is related to the existence of a metastable region of liquid immiscibility at sub-liquidus temperatures which is detectable by transmission electron microscopy (TEM) (Fig. 1).

Dechannealing Study of Nanocrystalline Si:H Layers Produced by High Dose Hydrogen Irradiation of Silicon Crystals

1998 ◽  
Vol 536 ◽  
Author(s):  
V. P. Popov ◽  
A. K. Gutakovsky ◽  
I. V. Antonova ◽  
K. S. Zhuravlev ◽  
E. V. Spesivtsev ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rutherford Backscattering Spectrometry ◽  
Nanocrystalline Structure ◽  
Structural Defects ◽  
High Dose ◽  
Silicon Crystals ◽  
Strong Energy ◽  
Transmission Electron ◽  
Hydrogen Implantation

AbstractA study of Si:H layers formed by high dose hydrogen implantation (up to 3x107cm-2) using pulsed beams with mean currents up 40 mA/cm2 was carried out in the present work. The Rutherford backscattering spectrometry (RBS), channeling of He ions, and transmission electron microscopy (TEM) were used to study the implanted silicon, and to identify the structural defects (a-Si islands and nanocrystallites). Implantation regimes used in this work lead to creation of the layers, which contain hydrogen concentrations higher than 15 at.% as well as the high defect concentrations. As a result, the nano- and microcavities that are created in the silicon fill with hydrogen. Annealing of this silicon removes the radiation defects and leads to a nanocrystalline structure of implanted layer. A strong energy dependence of dechanneling, connected with formation of quasi nanocrystallites, which have mutual small angle disorientation (<1.50), was found after moderate annealing in the range 200-500°C. The nanocrystalline regions are in the range of 2-4 nm were estimated on the basis of the suggested dechanneling model and transmission electron microscopy (TEM) measurements. Correlation between spectroscopic ellipsometry, visible photoluminescence, and sizes of nanocrystallites in hydrogenated nc-Si:H is observed.

Investigation of Switching Mechanism in HfO2-Based Oxide Resistive Memories by In-Situ Transmission Electron Microscopy and Electron Energy Loss Spectroscopy

2017 ◽  
Author(s):  
T. Dewolf ◽  
D. Cooper ◽  
N. Bernier ◽  
V. Delaye ◽  
A. Grenier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Hafnium Dioxide ◽  
Switching Mechanism ◽  
Transmission Electron ◽  
Electron Energy Loss

Abstract Forming and breaking a nanometer-sized conductive area are commonly accepted as the physical phenomenon involved in the switching mechanism of oxide resistive random access memories (OxRRAM). This study investigates a state-of-the-art OxRRAM device by in-situ transmission electron microscopy (TEM). Combining high spatial resolution obtained with a very small probe scanned over the area of interest of the sample and chemical analyses with electron energy loss spectroscopy, the local chemical state of the device can be compared before and after applying an electrical bias. This in-situ approach allows simultaneous TEM observation and memory cell operation. After the in-situ forming, a filamentary migration of titanium within the dielectric hafnium dioxide layer has been evidenced. This migration may be at the origin of the conductive path responsible for the low and high resistive states of the memory.

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