Effect of hydrogen peroxide on hydrofluoric acid etching of high-k materials: ESR investigations

2005 ◽  
Vol 351 (18) ◽  
pp. 1559-1564 ◽  
Author(s):  
V. Lowalekar ◽  
S. Raghavan
Keyword(s):  
Hydrogen Peroxide ◽  
Hydrofluoric Acid ◽  
Acid Etching ◽  
High K ◽  
High K Materials

The slow oxidation of methane

1956 ◽  
Vol 235 (1201) ◽  
pp. 158-173 ◽  
Keyword(s):  
Activation Energy ◽  
Hydrogen Peroxide ◽  
Induction Period ◽  
Hydrofluoric Acid ◽  
Pressure Rise ◽  
Pressure Change ◽  
Kcal Mole ◽  
Gaseous Products ◽  
Oxidation Of Methane ◽  
Reproducible Manner

Mixtures of methane and oxygen behave in a reproducible manner at temperatures of 440 to 520°C and initial pressures of 100 to 350 mm when reacting in Pyrex vessels freshly cleaned with hydrofluoric acid. The apparent order of the reaction ranged from 2∙3 to 2∙6 and the overall activation energy from 29 to 41 kcal/mole. Analyses of the products formed have been made, together with measurements of pressure change. Formaldehyde is formed from the commencement of the reaction including the induction period, but its concentra­tion reaches a maximum near the stage where the pressure rise is a maximum, and then falls off. Hydrogen peroxide is also formed, less rapidly in the earliest stage, but its rate of formation overtakes that of formaldehyde and it reaches an even higher concentration. No other peroxides were detected, nor was methanol found. Hydrogen was present in the gaseous products. These observations are not in full accord with some of the conclusions derived from earlier investigations.

scholarly journals Four chemical methods of porcelain conditioning and their influence over bond strength and surface integrity

2015 ◽  
Vol 20 (4) ◽  
pp. 51-56 ◽  
Author(s):  
João Paulo Fragomeni Stella ◽  
Andrea Becker Oliveira ◽  
Lincoln Issamu Nojima ◽  
Mariana Marquezan
Keyword(s):  
Phosphoric Acid ◽  
Bond Strength ◽  
Surface Integrity ◽  
Hydrofluoric Acid ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Acid Etching ◽  
Ceramic Surface ◽  
Surface Conditioning ◽  
Phosphoric Acid Etching

OBJECTIVE: To assess four different chemical surface conditioning methods for ceramic material before bracket bonding, and their impact on shear bond strength and surface integrity at debonding.METHODS: Four experimental groups (n = 13) were set up according to the ceramic conditioning method: G1 = 37% phosphoric acid etching followed by silane application; G2 = 37% liquid phosphoric acid etching, no rinsing, followed by silane application; G3 = 10% hydrofluoric acid etching alone; and G4 = 10% hydrofluoric acid etching followed by silane application. After surface conditioning, metal brackets were bonded to porcelain by means of the Transbond XP system (3M Unitek). Samples were submitted to shear bond strength tests in a universal testing machine and the surfaces were later assessed with a microscope under 8 X magnification. ANOVA/Tukey tests were performed to establish the difference between groups (α= 5%).RESULTS: The highest shear bond strength values were found in groups G3 and G4 (22.01 ± 2.15 MPa and 22.83 ± 3.32 Mpa, respectively), followed by G1 (16.42 ± 3.61 MPa) and G2 (9.29 ± 1.95 MPa). As regards surface evaluation after bracket debonding, the use of liquid phosphoric acid followed by silane application (G2) produced the least damage to porcelain. When hydrofluoric acid and silane were applied, the risk of ceramic fracture increased.CONCLUSIONS: Acceptable levels of bond strength for clinical use were reached by all methods tested; however, liquid phosphoric acid etching followed by silane application (G2) resulted in the least damage to the ceramic surface.

Composition Quantification of Microelectronics Multilayer Thin Films by EDX: Toward Small Scale Analysis

2009 ◽  
Vol 1184 ◽  
Author(s):  
Thierry Conard ◽  
Kai Arstila ◽  
Thomas Hantschel ◽  
Alexis Franquet ◽  
Wilfried Vandervorst ◽  
...  
Keyword(s):  
Gate Dielectric ◽  
Small Scale ◽  
Quantitative Composition ◽  
Composition Analysis ◽  
Multilayer Thin Films ◽  
Large Area ◽  
Fast Analysis ◽  
Metal Gates ◽  
High K ◽  
High K Materials

AbstractIn order to continuously improve the performances of microelectronics devices through scaling, SiO2 is being replaced by high-k materials as gate dielectric; metal gates are replacing poly-Si. This leads to increasingly more complex stacks. For future generations, the replacement of Si as a substrate by Ge and/or III/V material is also considered. This also increases the demand on the metrology tools as a thorough characterization, including composition and thickness is thus needed. Many different techniques exist for composition analysis. They usually require however large area for the analysis, complex instrumentation and can be time consuming. EDS (Energy Dispersive Spectroscopy) when coupled to Scanning Electron Microscopy (SEM) has the potential to allow fast analysis on small scale areas.In this work, we evaluate the possibilities of EDS for thin film analysis based on an intercomparison of composition analysis with different techniques. We show that using proper modeling, high quality quantitative composition and thickness of multilayers can be achieved.

scholarly journals Acid Etching as Surface Treatment Method for Luting of Glass-Ceramic Restorations, part 1: Acids, Application Protocol and Etching Effectiveness

2018 ◽  
Vol 6 (3) ◽  
pp. 568-573 ◽  
Author(s):  
Emilija Barjaktarova-Valjakova ◽  
Anita Grozdanov ◽  
Ljuben Guguvcevski ◽  
Vesna Korunoska-Stevkovska ◽  
Biljana Kapusevska ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Glass Ceramic ◽  
Hydrofluoric Acid ◽  
Treatment Method ◽  
Acid Etching ◽  
Etching Time ◽  
Ceramic Surface ◽  
Adhesive Luting ◽  
Ceramic Restorations ◽  
Etching Effect

AIM: The purpose of this review is to represent acids that can be used as surface etchant before adhesive luting of ceramic restorations, placement of orthodontic brackets or repair of chipped porcelain restorations. Chemical reactions, application protocol, and etching effect are presented as well.STUDY SELECTION: Available scientific articles published in PubMed and Scopus literature databases, scientific reports and manufacturers' instructions and product information from internet websites, written in English, using following search terms: “acid etching, ceramic surface treatment, hydrofluoric acid, acidulated phosphate fluoride, ammonium hydrogen bifluoride”, have been reviewed.RESULTS: There are several acids with fluoride ion in their composition that can be used as ceramic surface etchants. The etching effect depends on the acid type and its concentration, etching time, as well as ceramic type. The most effective etching pattern is achieved when using hydrofluoric acid; the numerous micropores and channels of different sizes, honeycomb-like appearance, extruded crystals or scattered irregular ceramic particles, depending on the ceramic type, have been detected on the etched surfaces.CONCLUSION: Acid etching of the bonding surface of glass - ceramic restorations is considered as the most effective treatment method that provides a reliable bond with composite cement. Selective removing of the glassy matrix of silicate ceramics results in a micromorphological three-dimensional porous surface that allows micromechanical interlocking of the luting composite.

Enlargement of diatom frustules pores by hydrofluoric acid etching at room temperature

2011 ◽  
Vol 46 (17) ◽  
pp. 5665-5671 ◽  
Author(s):  
Deyuan Zhang ◽  
Yu Wang ◽  
Wenqiang Zhang ◽  
Junfeng Pan ◽  
Jun Cai
Keyword(s):  
Hydrofluoric Acid ◽  
Room Temperature ◽  
Acid Etching

scholarly journals Silane Heat Treatment Could Eliminate the Hydrofluoric Acid Etching of Lithium Disilicate Overlays: A Four-Year Follow-Up

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Spartak Spasov Yanakiev ◽  
Mirela Borislavova Marinova-Takorova
Keyword(s):  
Heat Treatment ◽  
Bond Strength ◽  
Hydrofluoric Acid ◽  
Lithium Disilicate ◽  
Acid Etching ◽  
Preparation Technique ◽  
Ceramic Surface ◽  
Dental Adhesive ◽  
Ceramic Bond

A four-year follow-up of a novel silane heat treatment method for bonding lithium disilicate overlays to tooth structures without hydrofluoric acid etching of the ceramic surface is presented in this case report. Silane heat treatment modifies the silane layer and thus enhances resin ceramic bond strength without hydrofluoric acid etching. The standard ceramic preparation technique prior to bonding silicate ceramics to tooth structure is hydrofluoric acid etching and applying a silane coupling agent, followed by dental adhesive. In this case, the micromechanical roughening of the ceramic surface was performed by air abrasion with Al2O3. Silane heat treatment with constant 120°C airflow, applied for 60 sec, followed by dental adhesive application enhanced the resin-ceramic bond strength. After a four-year follow-up, the restorations’ clinical appearance could be defined as excellent/very good according to the FDI clinical criteria for the evaluation of direct and indirect restorations. This clinical result supports many in vitro studies regarding the resin-ceramic bond strength and durability obtained through postsilanization heat treatment.

Study on deposition kinetics of high-K materials by X-ray fluorescence techniques

2004 ◽  
Vol 59 (8) ◽  
pp. 1183-1187 ◽  
Author(s):  
Caterina Carpanese ◽  
Barbara Crivelli ◽  
Massimo Caniatti
Keyword(s):  
X Ray ◽  
Deposition Kinetics ◽  
Fluorescence Techniques ◽  
High K ◽  
High K Materials ◽  
Kinetics Of

Prevention of Unexpected Oxidation of Metal Layer by Removing Hydrogen Peroxide from Ultrapure Water and Diluted Hydrofluoric Acid

2014 ◽  
Vol 219 ◽  
pp. 221-224
Author(s):  
Daisaku Yaon ◽  
Masami Murayama ◽  
Hikaru Kobayashi ◽  
Koji Yamanaka
Keyword(s):  
Hydrogen Peroxide ◽  
Hydrofluoric Acid ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Metal Layer ◽  
Space Velocity ◽  
High Flow ◽  
Manufacturing Processes ◽  
Ultrapure Water

Ultrapure water (UPW) is widely used for rinsing wafers and diluting chemicals in semiconductor manufacturing processes. The quality of UPW is severely controlled, but the generation of hydrogen peroxide (H2O2) as a impurity is inevitable due to the ultraviolet irradiation in a UPW production system (Figure 1). In our survey, it is revealed that the concentration of H2O2 in UPW reaches to 10~40 μg/L level. Considering the situation, we have developed a palladium-loaded monolithic anion exchange resin (Pd-M) as a catalyst that is able to remove H2O2 from UPW down to below 1 μg/L at an extremely high flow rate (space velocity SV = 6,000 h-1), with no detectable elution of impurities [1, 2]. Furthermore, we have found that the dissolution rate of copper which is easy to be corroded oxidatively in CO2-dissolved water (CO2 UPW) [3] can be decreased to one-third by removal of H2O2 from CO2 UPW using Pd-M catalyst [4]. In this study, we present the effects of H2O2 removal from UPW and diluted hydrofluoric acid (DHF) on the surfaces of copper, molybdenum and silicon.

Etching Volume Effect on the Morphology of Silicon Etched by Metal-Assisted Chemical Method

2012 ◽  
Vol 217-219 ◽  
pp. 1141-1145 ◽  
Author(s):  
Wei Wang ◽  
Li Juan Zhao ◽  
Ping Xin Song ◽  
Ying Jiu Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Formation Mechanism ◽  
Ag Nanoparticles ◽  
Hydrofluoric Acid ◽  
Chemical Method ◽  
Volume Effect ◽  
Etching Solution ◽  
Si Substrates ◽  
Si Nanostructures

Assisted by Ag nanoparticles, Si substrates were etched in aqueous solutions containing hydrofluoric acid (HF) and hydrogen peroxide (H2O2) with different volumes of etching solution. The etching morphology of Si wafers was found to be affected by the volumes. In etching solutions with smaller volume, the pores were created; in etching solutions with larger volume, the nanostructure composed of nanowires and nanopores (pores+wires nanostructure) were generated. In addition, the lengths of these Si nanostructures increased with the increase of the etching volume. Possible formation mechanism for this phenomenon was discussed.

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