Changing Segregation Coefficients During Ion Beam Induced Epitaxy of Amorphous Si

1990 ◽  
Vol 201 ◽  
Author(s):  
J. S. Custer ◽  
Michael O. Thompson ◽  
D. C. Jacobson ◽  
J. M. Poate
Keyword(s):  
Early Stage ◽  
Ion Beam ◽  
Interface Velocity ◽  
Segregation Coefficient ◽  
Temperature Dependent ◽  
Segregation Process ◽  
Standard Models ◽  
Amorphous Si ◽  
Kinetic Trapping ◽  
Impurity Profiles

AbstractIon beam induced epitaxial crystallization of Au and Ag doped amorphous Si results in segregation and trapping of the impurity. Combining the measured interface velocity and impurity profiles in segregation simulations provides a measure of the segregation coefficient k during growth. To adequately match the experimental profiles, k must increase during the early stage of growth until saturating at a temperature dependent value. This segregation process cannot be explained within standard models where k depends on the inteface velocity (kinetic trapping) or the interface impurity concentration (thermodynamic solubility). Instead the data suggests that the number of trapping sites at the interface increases during the initial stages of ion beam induced growth. We present several possible mechanisms for this trapping increase and discuss their significance in ion beam and thermal epitaxy models.

Changing Segregation Coefficients During Ion Beam Induced Epitaxy of Amorphous Si

1990 ◽  
Vol 205 ◽  
Author(s):  
J. S. Custer ◽  
Michael O. Thompson ◽  
D. C. Jacobson ◽  
J. M. Poate
Keyword(s):  
Early Stage ◽  
Ion Beam ◽  
Interface Velocity ◽  
Segregation Coefficient ◽  
Temperature Dependent ◽  
Segregation Process ◽  
Standard Models ◽  
Amorphous Si ◽  
Kinetic Trapping ◽  
Impurity Profiles

AbstractIon beam induced epitaxial crystallization of Au and Ag doped amorphous Si results in segregation and trapping of the impurity. Combining the measured interface velocity and impurity profiles in segregation simulations provides a measure of the segregation coefficient k during growth. To adequately match the experimental profiles, k must increase during the early stage of growth until saturating at a temperature dependent value. This segregation process cannot be explained within standard models where k depends on the inteface velocity (kinetic trapping) or the interface impurity concentration (thermodynamic solubility). Instead the data suggests that the number of trapping sites at the interface increases during the initial stages of ion beam induced growth. We present several possible mechanisms for this trapping increase and discuss their significance in ion beam and thermal epitaxy models.

Interface Velocity and Noble Metal Segregation During Ion Beam Induced Epitaxial Crystallization

1989 ◽  
Vol 157 ◽  
Author(s):  
J. S. Custer ◽  
Michael O. Thompson ◽  
D. C. Jacobson ◽  
J. M. Poate
Keyword(s):  
Solid Phase ◽  
Ion Beam ◽  
Interface Velocity ◽  
Solid Phase Epitaxy ◽  
Segregation Coefficient ◽  
Time Resolved ◽  
Interfacial Segregation ◽  
Amorphous Si ◽  
Impurity Profiles

ABSTRACTThe interface velocity of Au and Ag doped amorphous Si during ion beam induced epitaxy was measured using in situ time resolved reflectivity. Interfacial segregation coefficients were determined as a function of composition from numerical simulations. At 320°C Au impurities enhanced the velocity by up to a factor of 2.5 compared to the intrinsic case. Silver slightly retarded re-growth by 10 %. These effects are qualitatively similar to the case of thermal solid phase epitaxy. Using the measured impurity profiles and interface velocity, computer simulations relate the segregation coefficient to the concentrations of the impurity at the interface. In both cases, the segregation coefficient increases with increasing interfacial impurity concentration.

Electronic Properties of Bismuth Nanowires

2001 ◽  
Vol 679 ◽  
Author(s):  
Stephen B. Cronin ◽  
Yu-Ming Lin ◽  
Oded Rabin ◽  
Marcie R. Black ◽  
Gene Dresselhaus ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Band Structure ◽  
Temperature Dependence ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Temperature Dependent ◽  
Si Substrates ◽  
Bismuth Nanowires ◽  
Bi Nanowire ◽  
Anodic Alumina Templates

ABSTRACTThe pressure filling of anodic alumina templates with molten bismuth has been used to synthesize single crystalline bismuth nanowires with diameters ranging from 7 to 200nm and lengths of 50μm. The nanowires are separated by dissolving the template, and electrodes are affixed to single Bi nanowires on Si substrates. A focused ion beam (FIB) technique is used first to sputter off the oxide from the nanowires with a Ga ion beam and then to deposit Pt without breaking vacuum. The resistivity of a 200nm diameter Bi nanowire is found to be only slightly greater than the bulk value, while preliminary measurements indicate that the resistivity of a 100nm diameter nanowire is significantly larger than bulk. The temperature dependence of the resistivity of a 100nm nanowire is modeled by considering the temperature dependent band parameters and the quantized band structure of the nanowires. This theoretical model is consistent with the experimental results.

scholarly journals Localizing Heat-Generating Defects Using Fluorescent Microthermal Imaging

1996 ◽  
Author(s):  
P. Tangyunyong ◽  
A.Y. Liang ◽  
A.W. Righter ◽  
D.L. Barton ◽  
J.M. Soden
Keyword(s):  
Failure Analysis ◽  
Focused Ion Beam ◽  
Uv Light ◽  
Ion Beam ◽  
Sample Surface ◽  
Analysis Tool ◽  
Temperature Dependent ◽  
Root Cause ◽  
Ideal Situation ◽  
Sem Imaging

Abstract Fluorescent microthermal imaging (FMI) involves coating a sample surface with a thin fluorescent film that, upon exposure to UV light source, emits temperature-dependent fluorescence [1-7]. The principle behind FMI was thoroughly reviewed at the ISTFA in 1994 [8, 9]. In two recent publications [10,11], we identified several factors in film preparation and data processing that dramatically improved the thermal resolution and sensitivity of FMI. These factors include signal averaging, the use of base mixture films, film stabilization and film curing. These findings significantly enhance the capability of FMI as a failure analysis tool. In this paper, we show several examples that use FMI to quickly localize heat-generating defects ("hot spots"). When used with other failure analysis techniques such as focused ion beam (FIB) cross sectioning and scanning electron microscope (SEM) imaging, we demonstrate that FMI is a powerful tool to efficiently identify the root cause of failures in complex ICs. In addition to defect localization, we use a failing IC to determine the sensitivity of FMI (i.e., the lowest power that can be detected) in an ideal situation where the defects are very localized and near the surface.

Ion-Beam-Induced Epitaxy and Solute Segregation at the Si Crystal-Amorphous Interface

1988 ◽  
Vol 128 ◽  
Author(s):  
J. M. Poate ◽  
D. C. Jacobson ◽  
F. Priolo ◽  
Michael O. Thompson
Keyword(s):  
Crystal Growth ◽  
Growth Process ◽  
Ion Beam ◽  
Solute Segregation ◽  
Ion Beams ◽  
Temperature Range ◽  
Crystal Growth Process ◽  
Amorphous Si ◽  
And Diffusion ◽  
Diffusion Of Impurities

ABSTRACTSegregation and diffusion of impurities in amorphous Si during furnace and ion-beam-induced epitaxy will be discussed. The use of ion beams to enhance the crystal growth process has resulted in novel behavior for fast diffusers such as Au. Diffusion is enhanced in the temperature range 300–700 K with activation energies ∼0.3 eV. Segregation and trapping are analogous to behavior at liquid-solid interfaces

Early stage of ripple formation on Ge(001) surfaces under near-normal ion beam sputtering

2007 ◽  
Vol 19 (3) ◽  
pp. 035304 ◽  
Author(s):  
D Carbone ◽  
A Alija ◽  
O Plantevin ◽  
R Gago ◽  
S Facsko ◽  
...  
Keyword(s):  
Early Stage ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Ripple Formation ◽  
Beam Sputtering

Photoluminescence (PL) and Optically Detected Magnetic Resonance (ODMR) Study of Visible Light Emission from Porous Si

1991 ◽  
Vol 256 ◽  
Author(s):  
P. A. Lane ◽  
L. S. Swanson ◽  
J. Shinar ◽  
S. Chumbley
Keyword(s):  
Light Emission ◽  
Porous Si ◽  
Temperature Dependent ◽  
X Band ◽  
Amorphous Si ◽  
Optically Detected ◽  
Increasing Temperature ◽  
Hydrogenated Amorphous ◽  
Visible Light Emission ◽  
Si Wafer

ABSTRACTThe photoluminescence (PL) and X-band ODMR of porous Si layers is described and discussed. The layers were prepared by anodizing the (100) face of a Si wafer at 20 mA/cm2 in 20% HF for 5 mai and passively soaking them in 36% HF for up to 10 hrs. The PL was broad and featureless, extending from ˜1.5 to ˜2.1 eV and peaking at 1.68 eV. Its intensity slightly increased upon cooling to 90 K, and then strongly decreased at lower temperatures. A ˜20 G wide asymmetric PL-enhancing ODMR was observed at g ˜2.0031 ±I 0.0009, which could be fit to a sum of two Gaussians. Their g-values were slightly temperature dependent. The ODMR intensity strongly decreased with increasing temperature, and was unobservable above ˜80 K. The results are compared to the optical properties of hydrogenated amorphous Si.

Changing the Structural State of Amorphous Silicon by Ion Irradiation

1989 ◽  
Vol 157 ◽  
Author(s):  
S. Roorda ◽  
W.C. Sinke ◽  
J.M. Poate ◽  
D.C. Jacobson ◽  
S. Dierker ◽  
...  
Keyword(s):  
Structural Relaxation ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Ion Beams ◽  
Nuclear Collision ◽  
Important Ingredient ◽  
Scanning Calorimetry ◽  
Amorphous Si ◽  
Induced Defects ◽  
Kinetics Of

ABSTRACTIon beams of keV and MeV energies have been used to bombard amorphous Si (a-Si), which had previously been annealed (‘relaxed’). Analysis by Raman spectroscopy and differential scanning calorimetry shows that when 1 out of every 20 Si atoms is displaced by a nuclear collision, the a-Si returns to its unrelaxed state and cannot be distinguished from as implanted a-Si. Moreover, the kinetics of the heat release on annealing of similarly bombarded crystalline Si (c-Si) are qualitatively identical to those of structural relaxation in a-Si. This implies that the population of ion beam induced defects in a-Si is very similar to that in c-Si. It also shows that defect annihilation is an important ingredient in the mechanism of structural relaxation of a-Si.

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