In-Situ Characterization of the Surface State Density by Photoluminescence During Electrochemical Treatments of Silicon Surfaces

1996 ◽  
Vol 451 ◽  
Author(s):  
T. Dittrich ◽  
V. Y. Timoshenko ◽  
J. Rappich
Keyword(s):  
Anodic Oxidation ◽  
Surface State ◽  
Surface States ◽  
State Density ◽  
Silicon Surfaces ◽  
In Situ Characterization ◽  
Surface State Density ◽  
Pl Intensity

ABSTRACTThe photoluminescence (PL) of c-Si is probed stroboscopically with single pulses of a N2 laser during electrochemical treatments (hydrogenation and anodic oxidation). The PL intensity of indirect semiconductors such as Si is controlled by the non-radiative surface and bulk recombination. By this reason the density of surface states can be estimated for unknown surfaces by using a calibrated standard. The surface state density of a hydrogenated Si surface increases by exchanging the electrolyte by gaseous N2 or water.

Copper Contamination Mechanism of Silicon Substrates from HF Solutions

1997 ◽  
Vol 52 (6-7) ◽  
pp. 465-476 ◽  
Author(s):  
Valérie Bertagna ◽  
François Rouelle ◽  
Marius Chemla
Keyword(s):  
Copper Ions ◽  
Open Circuit ◽  
Silicon Surfaces ◽  
Silicon Substrates ◽  
In Situ Characterization ◽  
Quantitative Measurements ◽  
Corrosion Pits ◽  
Voltammetric Measurements

The contamination of silicon wafers from dilute HF solutions containing ultratrace levels of metallic ion impurities is a subject of constant interest. The mechanism of copper electroless deposition from HF onto monocrystalline silicon was investigated using a new electrochemical cell, which proved to be a very sensitive detector for in situ characterization of silicon surfaces. Upon addition of copper trace amounts, the open-circuit potential was observed to shift rapidly towards more positive values at a rate nearly proportional to the copper concentration. All potential/ time curves tend to reach a limiting value of the potential, while quantitative measurements of radioactive tracers revealed that during a few tens of minutes, copper ions were continuously reduced on the silicon surface. Electrochemical potentials and voltammetric measurements were interpreted in terms of the mixed potential theory and led to the conclusion that copper nuclei act as a catalyst which enhances the cathodic activity for protons reduction. The model was supported by AFM observations which demonstrated the initiation of corrosion pits around the nuclei.

Determination of surface barrier height and surface state density in GaN films grown on sapphire substrates

2004 ◽  
Vol 831 ◽  
Author(s):  
Seong-Eun Park ◽  
Joseph J. Kopanski ◽  
Youn-Seon Kang ◽  
Lawrence H. Robins ◽  
Hyun-Keel Shin
Keyword(s):  
Barrier Height ◽  
Surface State ◽  
Deep Level ◽  
Surface States ◽  
State Density ◽  
Beam Power ◽  
Surface Barrier ◽  
Surface State Density ◽  
Sapphire Substrates ◽  
Surface Electric Field

ABSTRACTPhotoreflectance (PR) modulation spectroscopy was performed to investigate surface properties of GaN films grown on sapphire substrates. From the period of the Franz-Keldysh oscillations, the surface electric field across the GaN space charge region was found to be (197 ± 11) kV/cm, which corresponds to a surface state density of 1.0×1012 cm−2. A surface barrier height of 0.71 eV was determined by fitting the dependence of the PR intensities on pump beam power density. We suggest that a deep level is formed at 2.68 eV above the GaN valence band edge due to the large density of surface states.

Characterization of nitrided silicon-silicon dioxide interfaces

1999 ◽  
Vol 591 ◽  
Author(s):  
M. L. Polignano ◽  
M. Alessandri ◽  
D. Brazzelli ◽  
B. Crivelli ◽  
G. Ghidini ◽  
...  
Keyword(s):  
Surface State ◽  
Surface Recombination ◽  
State Density ◽  
Constant Current ◽  
Surface Recombination Velocity ◽  
State Reduction ◽  
Surface State Density ◽  
Recombination Velocity ◽  
Silicon Interface

ABSTRACTA newly-developed technique for the simultaneos characterization of the oxide-silicon interface properties and of bulk impurities was used for a systematic study of the nitridation process of thin oxides. This technique is based upon surface recombination velocity measurements, and does not require the formation of a capacitor structure, so it is very suitable for the characterization of as-grown interfaces.Oxides grown both in dry and in wet enviroments were considered, and nitridation processes in N2O and in NO were compared to N2 annealing processes. The effect of nitridation temperature and duration were also studied, and RTO/RTN processes were compared to conventional furnace nitridation processes.Surface recombination velocity was correlated with nitrogen concentration at the oxide-silicon interface obtained by Secondary Ion Mass Spectroscopy (SIMS) measurements. Surface recombination velocity (hence surface state density) decreases with increasing nitrogen pile-up at the oxide-silicon interface, indicating that in nitrided interfaces surface state density is limited by nitridation. NO treatments are much more effective than N2O treatments in the formation of a nitrogen-rich interface layer and, as a consequence, in surface state reduction.Surface state density was measured in fully processed wafers before and after constant current stress. After a complete device process surface states are annealed out by hydrogen passivation, however they are reactivated by the electrical stress, and surface state results after stress were compared with data of surface recombination velocity in as-processed wafers.

Characterization of the glycoconjugates of boar testis and epididymis

Reproduction ◽  
2000 ◽  
pp. 325-335 ◽  
Author(s):  
A Calvo ◽  
LM Pastor ◽  
S Bonet ◽  
E Pinart ◽  
M Ventura
Keyword(s):  
Ricinus Communis ◽  
Lectin Histochemistry ◽  
Apical Part ◽  
Seminiferous Tubules ◽  
In Situ Characterization ◽  
Intense Staining ◽  
Terminal Galactose ◽  
Boar Spermatozoa

Lectin histochemistry was used to perform in situ characterization of the glycoconjugates present in boar testis and epididymis. Thirteen horseradish peroxidase- or digoxigenin-labelled lectins were used in samples obtained from healthy fertile boars. The acrosomes of the spermatids were stained intensely by lectins with affinity for galactose and N-acetyl-galactosamine residues, these being soybean, peanut and Ricinus communis agglutinins. Sertoli cells were stained selectively by Maackia ammurensis agglutinin. The lamina propria of seminiferous tubules showed the most intense staining with fucose-binding lectins. The Golgi area and the apical part of the principal cells of the epididymis were stained intensely with many lectins and their distribution was similar in the three zones of the epididymis. On the basis of lectin affinity, both testis and epididymis appear to have N- and O-linked glycoconjugates. Spermatozoa from different epididymal regions showed different expression of terminal galactose and N-acetyl-galactosamine. Sialic acid (specifically alpha2,3 neuraminic-5 acid) was probably incorporated into spermatozoa along the extratesticular ducts. These findings indicate that the development and maturation of boar spermatozoa are accompanied by changes in glycoconjugates. As some lectins stain cellular or extracellular compartments specifically, these lectins could be useful markers in histopathological evaluation of diseases of boar testis and epididymis.

In Situ Characterization of Soils for Prediction of Stress-Strain Relationship

1983 ◽  
Author(s):  
K. Arulanandan ◽  
Y. Dafalias ◽  
L. R. Herrmann ◽  
A. Anandarajah ◽  
N. Meegoda
Keyword(s):  
In Situ Characterization ◽  
Stress Strain ◽  
Strain Relationship

scholarly journals In-situ characterization of highly reversible phase transformation by synchrotron X-ray Laue microdiffraction

2016 ◽  
Vol 108 (21) ◽  
pp. 211902 ◽  
Author(s):  
Xian Chen ◽  
Nobumichi Tamura ◽  
Alastair MacDowell ◽  
Richard D. James
Keyword(s):  
Phase Transformation ◽  
In Situ Characterization ◽  
X Ray ◽  
Reversible Phase ◽  
Laue Microdiffraction

In Situ Characterization of Catalysis and Electrocatalysis Using APXPS

ACS Catalysis ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 1464-1484 ◽  
Author(s):  
Yong Han ◽  
Hui Zhang ◽  
Yi Yu ◽  
Zhi Liu
Keyword(s):  
In Situ Characterization
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