The mechanisms underlying selective etching of a SiO2 layer over a Si or Si3N4 underlayer, a process of vital importance to modern integrated circuit fabrication technology, has been studied. Selective etching of SiO2-to-Si3N4 in various inductively coupled fluorocarbon plasmas (CHF3 , C2F6/C3F6 , and C3F6/H2) was performed, and the results compared to selective SiO2-to-Si etching. A fluorocarb...

OBJECTIVE This study determined the effects of various surface treatment modalities on the bond strength of composite resins to glass-ionomer cements. MATERIAL AND METHODS Conventional (Ketac Molar Quick Applicap) or resin-modified (Photac Fil Quick Aplicap) glass-ionomer cements were prepared. Two-step etch-rinse & bond adhesive (Adper Single Bond 2) or single-step self-etching adhesive (Adp...

We report the effect of N2 addition to C4F8 and C4F8 /Ar discharges on plasma etching rates of organosilicate glass ~OSG! and etch stop layer materials (Si3N4 and SiC!, and the results of surface chemistry studies performed in parallel. N2 addition exhibits different effects in C4F8 and C4F8 /Ar plasmas, which may be explained by a higher plasma density, electron temperature, and possibly, the ...

Contradictory evidence exists as to the acid necessary for producing optimum enamel etching on buccal tooth surfaces. The aims of this study were to (1) compare the etching abilities of four different acids; (2) identify the acid concentrations required for optimum etching; and (3) determine the concentration stability of phosphoric acid solutions. Crowns of caries-free molar teeth were pumiced...

The evolution of integrated circuits into the ultralarge scale integrated regime takes today’s 0.35 mm circuit design rules to even smaller values of 0.18 mm and beyond. As a consequence, photoresist masks are becoming thinner and even more prone to erosion by etching. For this work an I-line novolak resist was used. Etch rates for various process conditions using in situ ellipsometry were obta...

Dynamic electrochemical etching technique is optimized to produce tungsten tips with controllable shape and radius of curvature of less than 10 nm. Nascent features such as "dynamic electrochemical etching" and reverse biasing after "drop-off" are utilized, and "two-step dynamic electrochemical etching" is introduced to produce extremely sharp tips with controllable aspect ratio. Electronic cur...

In the current study, monocrystalline silicon nanowire arrays (SiNWs) were prepared through a metal-assisted chemical etching method of silicon wafers in an etching solution composed of HF and H2O2. Photoelectric properties of the monocrystalline SiNWs are improved greatly with the formation of the nanostructure on the silicon wafers. By controlling the hydrogen peroxide concentration in the et...

Introduction: Sealing pits and fissures was introduced as an approach to prevent occlusal caries for more than two decades. The aim of this study was to compare the microleakage of flow able resin reinforced glass ionomer (Ionoseal) with other materials used as fissure sealants. Methods: In this in vitro study, 50 premolar teeth of human free of any caries were selected. Fissurotomy was done...

Time-resolved extinction spectroscopy is employed to study the reaction kinetics in the shape-conversion reaction involving halide ions (including Cl(-), Br(-) and I(-)) etching (sculpturing) silver nanoplates. A series of time-resolved extinction spectra are obtained during the in situ etching process and the evolution of surface plasmon resonance (SPR) of the silver nanoparticles is analyzed....

A simple method for the fabrication of porous silicon (Si) by metal-assisted etching was developed using gold nanoparticles as catalytic sites. The etching masks were prepared by spin-coating of colloidal gold nanoparticles onto Si. An appropriate functionalization of the gold nanoparticle surface prior to the deposition step enabled the formation of quasi-hexagonally ordered arrays by self-ass...