Instability of Nanocavities in Disordered and Amorphous Silicon Under Ion Irradiation

1998 ◽  
Vol 540 ◽  
Author(s):  
X. Zhu ◽  
J.S. Williams ◽  
J.C. McCallum
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Amorphous Silicon ◽  
Irradiation Dose ◽  
Crystalline Silicon ◽  
Ion Irradiation ◽  
Rutherford Backscattering ◽  
Cross Sectional ◽  
Open Volume ◽  
Transmission Electron

AbstractIt has recently been shown that a band of nanocavities in crystalline silicon is eliminated during amorphization of the silicon surrounding this band [4]. In this study, we examine the effect of irradiation dose on nanocavity stability. Gettering of Au is used as a detector for open volume defects following annealing of irradiated samples. Rutherford backscattering and channeling and cross-sectional transmission electron microscopy have been used to analyse the samples. Cavities are only completely removed when the region surrounding the cavities is totally amorphized up to the surface. Partial amorphization leaves residual open volume defects.

Nano-Thermometry: Transmission Electron Microscopy of Femtosecond Laser Irradiated Co/Si Multilayer Thin Foils

2005 ◽  
Vol 899 ◽  
Author(s):  
Yoosuf Picard ◽  
Steven M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Amorphous Silicon ◽  
Heat Dissipation ◽  
Crystalline Silicon ◽  
Pulse Length ◽  
Multilayer Systems ◽  
Hole Edge ◽  
Thin Foils ◽  
Transmission Electron

AbstractPre-thinned foils composed of amorphous silicon and polycrystalline cobalt were irradiated using femtosecond pulse-length lasers at fluences sufficient for ablation (material removal). The resultant ablated hole and surrounding vicinity was studied using transmission electron microscopy to determine modifications to the structure. Evidence of cobalt silicide formation was observed within a 3 micron radius of the laser hole edge by use of selected area electron diffraction (SAED). In addition, elongated grains of crystalline silicon was observed within 500 nm of the laser hole edge, indicating melting of the amorphous silicon and heat dissipation slow enough to allow recyrstallization. This initial work demonstrates the use of pre-designed nanostructured multilayer systems as a method for nanoscale profiling of heat dissipation following pulsed laser irradiation.

Comparative Study of Structural Properties and Photoluminescence in InGaN Layers with a High in Content

1999 ◽  
Vol 595 ◽  
Author(s):  
A. Vantomme ◽  
M.F. Wu ◽  
S. Hogg ◽  
G. Langouche ◽  
K. Jacobs ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Comparative Study ◽  
Structural Properties ◽  
Rutherford Backscattering ◽  
Cross Sectional ◽  
Indium Concentration ◽  
Transmission Electron ◽  
Peak Energy

AbstractRutherford backscattering and channeling spectrometry (RBS), photoluminescence (PL) spectroscopy and transmission electron microscopy (TEM) have been used to investigate macroscopic and microscopic segregation in MOCVD grown InGaN layers. The PL peak energy and In content (measured by RBS) were mapped at a large numberof distinct points on the samples. An indium concentration of 40%, the highest measured in this work, corresponds to a PL peak of 710 nm, strongly suggesting that the lightemitting regions of the sample are very indium-rich compared to the average measured by RBS. Cross-sectional TEM observations show distinctive layering of the InGaN films. The TEM study further reveals that these layers consist of amorphous pyramidal contrast features with sizes of order 10 nm. The composition of these specific contrast features is shown to be In-rich compared to the nitride matrix.

Comparative study of structural properties and photoluminescence in InGaN layers with a high In content

2000 ◽  
Vol 5 (S1) ◽  
pp. 703-709
Author(s):  
A. Vantomme ◽  
M.F. Wu ◽  
S. Hogg ◽  
G. Langouche ◽  
K. Jacobs ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Comparative Study ◽  
Structural Properties ◽  
Rutherford Backscattering ◽  
Cross Sectional ◽  
Light Emitting ◽  
Indium Concentration ◽  
Transmission Electron ◽  
Peak Energy

Rutherford backscattering and channeling spectrometry (RBS), photoluminescence (PL) spectroscopy and transmission electron microscopy (TEM) have been used to investigate macroscopic and microscopic segregation in MOCVD grown InGaN layers. The PL peak energy and In content (measured by RBS) were mapped at a large number of distinct points on the samples. An indium concentration of 40%, the highest measured in this work, corresponds to a PL peak of 710 nm, strongly suggesting that the light-emitting regions of the sample are very indium-rich compared to the average measured by RBS. Cross-sectional TEM observations show distinctive layering of the InGaN films. The TEM study further reveals that these layers consist of amorphous pyramidal contrast features with sizes of order 10 nm. The composition of these specific contrast features is shown to be In-rich compared to the nitride matrix.

Comparative Thickness Measurements of Heterojunction Layers by Ellipsometric, RBS, and XTEM Analysis

1986 ◽  
Vol 77 ◽  
Author(s):  
J. A. Woollam ◽  
P. G. Snyder ◽  
A. W. McCOrmick ◽  
A. K. Rai ◽  
D. C. Ingram ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rutherford Backscattering ◽  
Angle Of Incidence ◽  
Gaas Sample ◽  
Cross Sectional ◽  
Variable Angle ◽  
Transmission Electron ◽  
Thickness Measurements

ABSTRACTVariable Angle of incidence Spectroscopie Ellipsometry (VASE), Rutherford Backscattering (RBS) and Cross-sectional Transmission Electron Microscopy (XTEM), are used to measure heterojunction layer thicknesses in an AlGaAs/GaAs sample. All three techniques yield the same thickness values within error limits.

Microstructural Evolution of Nickel Induced Crystallization of Amorphous Silicon

2002 ◽  
Vol 715 ◽  
Author(s):  
Kyu Ho Park ◽  
Young Woo Jeong ◽  
Hyun Ja Kwon ◽  
Jeong Soo Lee ◽  
Binn Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Amorphous Silicon ◽  
Microstructural Evolution ◽  
Crystalline Silicon ◽  
Transmission Electron ◽  
Si Films ◽  
Induced Crystallization

AbstractThe Ni silicide-mediated phase transformation of amorphous to crystalline silicon (c-Si) was studied using transmission electron microscopy. Amorphous silicon (a-Si) films coated with very thin Ni layer (∼10-1Å) were annealed at various temperatures. Randomly oriented NiSi2 precipitates were observed in the Ni deposited a-Si film annealed at 400°C. The nucleation of the epitaxial c-Si has occurred on the {111} faces of the octahedral NiSi2 precipitate at 430°C and then caused to the variation in the shape of the NiSi2 precipitates. During the growth of c-Si, the needle-like morphology developed from the migration of NiSi2 precipitates through the a-Si matrix leaving a trail of c-Si. The collision of a migrating NiSi2 precipitate with a stationary NiSi2 precipitates in the a-Si film gave rise to the change in the morphology of the growing Si grain and the formation of additional c-Si needles on variants of the <111> direction.

Microstructure of laser-irradiated, conducting Kapton polyimide

1995 ◽  
Vol 53 ◽  
pp. 502-503
Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Surface ◽  
Cross Sectional ◽  
General Utility ◽  
Transmission Electron ◽  
Considerable Debate ◽  
Potential Applications

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.

Ion thinning of integrated circuit transverse specimens for transmission electron microscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1426-1427
Author(s):  
F. Shaapur
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Integrated Circuit ◽  
Substrate Surface ◽  
Homogeneous Material ◽  
Material System ◽  
Ion Milling ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Motion Profile

Non-uniform ion-thinning of heterogenous material structures has constituted a fundamental difficulty in preparation of specimens for transmission electron microscopy (TEM). A variety of corrective procedures have been developed and reported for reducing or eliminating the effect. Some of these techniques are applicable to any non-homogeneous material system and others only to unidirectionalfy heterogeneous samples. Recently, a procedure of the latter type has been developed which is mainly based on a new motion profile for the specimen rotation during ion-milling. This motion profile consists of reversing partial revolutions (RPR) within a fixed sector which is centered around a direction perpendicular to the specimen heterogeneity axis. The ion-milling results obtained through this technique, as studied on a number of thin film cross-sectional TEM (XTEM) specimens, have proved to be superior to those produced via other procedures.XTEM specimens from integrated circuit (IC) devices essentially form a complex unidirectional nonhomogeneous structure. The presence of a variety of mostly lateral features at different levels along the substrate surface (consisting of conductors, semiconductors, and insulators) generally cause non-uniform results if ion-thinned conventionally.

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