Characterization of HF Treated (100) Si Surfaces by Surface Charge Analysis (SCA)

1992 ◽  
Vol 259 ◽  
Author(s):  
Jon T. Fitch
Keyword(s):  
Electrical Properties ◽  
Surface Charge ◽  
Chemical Bonding ◽  
Oxide Thickness ◽  
Silicon Surfaces ◽  
Native Oxide ◽  
Charge Analysis ◽  
The Stability ◽  
Over Time

ABSTRACTSurface Charge Analysis (SCA), and ellipsometry have been used to study the stability over time of HF treated (100) silicon surfaces as a function of the post-HF rinse time. Using SCA, the electrical properties of the chemical terminating layer of these silicon surfaces were measured. The surfaces which remained native oxide free the longest (−10 hours) had very low Qox and Dit values on the order of 1.0 × 1011/cm2 and 5.0 × 1010 eV−lcm−2, respectively. A good correlation was found between Dit and the native oxide thickness measured by ellipsometry. This and other results are discussed in terms of the chemical bonding on the silicon surfaces.

Chemical Control of Surfaces: From Fundamental Understanding to Practical Application

2012 ◽  
Vol 195 ◽  
pp. 65-70
Author(s):  
Melissa A. Hines
Keyword(s):  
Atomic Scale ◽  
Silicon Surfaces ◽  
Native Oxide ◽  
Native Oxide Layer ◽  
Microelectronics Industry ◽  
Industrial Adoption ◽  
Detrimental Impact ◽  
Metallic Impurities ◽  
Acidic Hydrogen

In the early days of the microelectronics industry, it became clear that even trace contaminants could have detrimental impact on the electronic properties of fabricated devices. This realization led to the development of the so-called RCA clean for silicon surfaces [], which uses sequential baths in basic and acidic hydrogen peroxide solutions, now known as SCA-1 and SCA-2, to oxidize organic materials, remove particulates, and bind metallic impurities. The detailed characterization of this process as well as its simplicity and economic viability soon led to its widespread industrial adoption. Although the RCA clean includes an optional etch in dilute HF between the two cleaning solutions to remove the native oxide layer, the overall process results in an extremely clean but electronically defectiveoxide-terminatedand thus extremely hydrophilic silicon surface, which we now know is quite rough on an atomic scale [].

scholarly journals Evolution of Metakaolin Thermal and Chemical Activation from Natural Kaolin

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 534 ◽  
Author(s):  
Isabel Sánchez ◽  
Isabel Sonsoles de Soto ◽  
Marina Casas ◽  
Raquel Vigil de la Villa ◽  
Rosario García-Giménez
Keyword(s):  
Thermal Activation ◽  
Chemical Activation ◽  
Pozzolanic Reaction ◽  
Stability Field ◽  
Optimal Conditions ◽  
Reaction Products ◽  
Icp Ms ◽  
The Stability ◽  
Over Time

In the present paper, we study the combined effect of thermal activation (600 °C/2 h and 750 °C/2 h) and chemical activation with 1% ZnO on the reactivity of metakaolinite (MK) obtained from natural kaolin. The phases are identified by chemical (ICP/MS), mineralogical (XRD), and morphological (SEM/EDX) characterization of all products, as well as the evolution and stability over time of the hydrated phases generated during the reaction, to determine their use as pozzolan in the manufacture of cements. The stability analysis for the kaolin/lime system activated chemically and thermally at 600 °C/2 h shows that the C-S-H gels are thermodynamically stable after one day of reaction, evolving the system to the stability field of stratlingite for the other analyzed times. At 750 °C/2 h, the thermodynamically stable reaction phases are C-S-H gels. Calcination at 600 °C/2 h and the addition of 1% ZnO are the optimal conditions for thermal and chemical activation, to improve the pozzolanic reaction and promote the replacing part of the cement for developing secondary reaction products.

Nanoparticle-Decorated Surfaces for the Study of Cell-Protein-Substrate Interactions

2004 ◽  
Vol 845 ◽  
Author(s):  
Jake D. Ballard ◽  
Ludovico M. Dell'Acqua-Bellavitis ◽  
Rena Bizios ◽  
Richard W. Siegel
Keyword(s):  
Silica Nanoparticles ◽  
Surface Coverage ◽  
Silicon Oxide ◽  
Substrate Surface ◽  
Silicon Surfaces ◽  
Native Oxide ◽  
Cell Protein ◽  
Fabrication And Characterization ◽  
Nanoscale Features

ABSTRACTThe present study was motivated by the need for accurately-controlled and well-characterized novel biomaterial formulations for the study of cell-protein-material interactions. For this purpose, the current research has focused on the design, fabrication and characterization of model native oxide-coated silicon surfaces decorated with silica nanoparticles of select sizes, and has examined the adhesion of osteoblasts and fibroblasts on these nanoparticle-decorated surfaces. The results demonstrate the capability to deposit nanoparticles of select diameters and substrate surface coverage onto native silicon oxide-coated silicon, the firm attachment of these nanoparticles to the underlying native silicon oxide, and that nanoparticle size and coverage modulate adhesion of osteoblasts and fibroblasts to these substrates. The material formulations tested provide a well-controlled and well-characterized set of model substrates needed to study the effects of nanoscale features on the functions of cells that are critical to the clinical fate of implantable biomaterials.

Different theoretical approaches at optical characterization of randomly rough silicon surfaces covered with native oxide layers

2018 ◽  
Vol 50 (11) ◽  
pp. 1230-1233 ◽  
Author(s):  
Ivan Ohlídal ◽  
Jiří Vohánka ◽  
Jan Mistrík ◽  
Martin Čermák ◽  
Daniel Franta
Keyword(s):  
Optical Characterization ◽  
Silicon Surfaces ◽  
Native Oxide ◽  
Oxide Layers ◽  
Theoretical Approaches

Atomic layer deposition of tungsten disulphide solid lubricant thin films

2004 ◽  
Vol 19 (12) ◽  
pp. 3443-3446 ◽  
Author(s):  
T.W. Scharf ◽  
S.V. Prasad ◽  
T.M. Mayer ◽  
R.S. Goeke ◽  
M.T. Dugger
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Solid Lubricant ◽  
Atomic Layer ◽  
Nucleation And Growth ◽  
Silicon Surfaces ◽  
Native Oxide ◽  
Tungsten Disulphide ◽  
Layer Deposition

The synthesis and characterization of crystalline tungsten disulphide (WS2) solid lubricant thin films grown by atomic layer deposition (ALD) using WF6 and H2S gas precursors was studied. A new catalytic route was established to promote nucleation and growth of WS2 films on silicon surfaces with native oxide. Scanning electron microscopy with energy dispersive spectroscopy and Raman spectroscopy were used to determine the film morphology, composition, and crystallinity. The films exhibited solid lubricating behavior with a steady-state friction coefficient of 0.04 in a dry nitrogen environment.

Monitoring Of HF/H2O Treated Silicon Surfaces Using Noncontact Surface Charge Measurements

1995 ◽  
Vol 386 ◽  
Author(s):  
P. Roman ◽  
D. Hwang ◽  
K. Torek ◽  
J. Ruzyllo ◽  
E. Kamieniecki
Keyword(s):  
Surface Charge ◽  
Silicon Surface ◽  
Positive Charge ◽  
Silicon Surfaces ◽  
Chemical Condition ◽  
Charged Species ◽  
Non Invasive ◽  
System A ◽  
Oxide Etching

ABSTRACTIn this work, a new commercial system allowing non-contact measurement of the surface charge is used to monitor the condition of the silicon surface following HF/water etch. Results obtained demonstrate that by monitoring changes of surface charge using this system, a truly non-invasive, instant and easy to carry out characterization of Si surfaces after HF/water etch can be accomplished. The results show that HF/water exposure adds positive charge to the silicon surface. Change in the surface charge, considered to be indicative of the change in the electro-chemical condition of the surface, appears to precede initiation of the oxide etching process, and is proposed to be a factor in initiating etching reactions that involve mainly negatively charged species.

scholarly journals Synthesis And Characterization Of SiO2, SnO2 And TiO2 Metal Oxide Shells Covering Cu2O Particles

2015 ◽  
Vol 60 (2) ◽  
pp. 1159-1163 ◽  
Author(s):  
Ri Yu ◽  
Jiyeon Yun ◽  
Yoojin Kim
Keyword(s):  
Synthesis And Characterization ◽  
Colloidal Solutions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Coated Nanoparticles ◽  
Transmission Electron ◽  
The Stability ◽  
Over Time

Abstract In this work is described a means of improving the chemical stability of Cu2O@SiO2, Cu2O@SnO2 and Cu2O@TiO2 materials. The SiO2, SnO2 and TiO2 coated samples were stable from pH 3 to pH 10 for up to seven days. To determine the stability of the coated nanoparticles, and their colloidal solutions under acidic and basic conditions, colloidal nanoparticle solutions with various pH values were prepared and monitored over time. Details of the effect of variations in pH on the phase stability of core-shell type Cu2O were characterized using transmission electron microscopy and X-ray diffraction.

TEM characterization of silicon epitaxial layer grown on Si-TaS2, eutectic composites

1991 ◽  
Vol 49 ◽  
pp. 802-803
Author(s):  
C.M. Sung ◽  
M. Levinson ◽  
M. Tabasky ◽  
K. Ostreicher ◽  
B.M. Ditchek
Keyword(s):  
Substrate Surface ◽  
Bulk Sample ◽  
Surface Cleaning ◽  
Native Oxide ◽  
Czochralski Growth ◽  
Ion Milling ◽  
Cross Sectional ◽  
Cleaning Methods ◽  
Field Emission Cathodes

Directionally solidified Si/TaSi2 eutectic composites for the development of electronic devices (e.g. photodiodes and field-emission cathodes) were made using a Czochralski growth technique. High quality epitaxial growth of silicon on the eutectic composite substrates requires a clean silicon substrate surface prior to the growth process. Hence a preepitaxial surface cleaning step is highly desirable. The purpose of this paper is to investigate the effect of surface cleaning methods on the epilayer/substrate interface and the characterization of silicon epilayers grown on Si/TaSi2 substrates by TEM.Wafers were cut normal to the <111> growth axis of the silicon matrix from an approximately 1 cm diameter Si/TaSi2 composite boule. Four pre-treatments were employed to remove native oxide and other contaminants: 1) No treatment, 2) HF only; 3) HC1 only; and 4) both HF and HCl. The cross-sectional specimens for TEM study were prepared by cutting the bulk sample into sheets perpendicular to the TaSi2 fiber axes. The material was then prepared in the usual manner to produce samples having a thickness of 10μm. The final step was ion milling in Ar+ until breakthrough occurred. The TEM samples were then analyzed at 120 keV using the Philips EM400T.

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