Dry etching techniques employing ion beam induced surface reaction and the possibility of highly charged ion beam in dry etching are described, and the preliminary work on dry etching of GaAs using highly charged ion (HCI) is also presented. In usual dry etching, total etch rate is a summation of the physical sputtering rate, the chemical etching rate, and the ion-induced chemical etching rate....

Dynamic etching methods for fabricating fibre optic tips are explored and modelled. By vertically translating the fibre during etching by an HF solution under an organic protective layer, a variety of tip shapes were created. The probe taper lengths, cone angles and geometrical probe shapes were measured in order to evaluate the dynamic meniscus etching process. Fibre motion, etching rate, meni...

objectives: this study aimed to compare the microleakage beneath metallic brackets following two different methods of enamel preparation and light curing. materials and methods: a total of 120 bovine deciduous lower incisors were randomly divided into four groups of 30 teeth. the preparations were as follows: group i: acid etching + transbond xt primer + direct illumination, group ii: acid etch...

objectives: this study aimed to determine the effect of surface treatments such as tooth reduction and extending the etching time on microtensile bond strength (µtbs) of composite resin to normal and fluorotic enamel after microabrasion. materials and methods: fifty non-carious anterior teeth were classified into two groups of normal and fluorotic (n=25) using thylstrup and fejerskov index (tfi...

Aim: To assess the influence of dental etching on the shear strength of different glass ionomer cements. Methods: The crown of 60 bovine incisors was prepared to obtain a flat, smooth surface, were attached to a PVC tube and randomly divided into six groups: Group 1 – Riva Self Cure without etching; Group II – Riva Self Cure with pre-etching; Group III – Maxxion R without etching; Group IV – Ma...

Research and development in semiconducting silicon carbide (SiC) technology has produced significant progress in the past five years in many areas: material (bulk and thin film) growth, device fabrication, and applications. A major factor in this rapid growth has been the development of SiC bulk crystals and the availability of crystalline substrates. Current leading applications for SiC device...

In this work, an accelerating etching method for glass named thermal electrical modified etching (TEM etching) is investigated. Based on the identification of the effect in anodic bonding, a novel method for glass structure micromachining is proposed using TEM etching. To validate the method, TEM-etched glasses are prepared and their morphology is tested, revealing the feasibility of the new me...

statement of problem: hemostatic agents may affect the micro-leakage of different adhesive systems. also, chlorhexidine has shown positive effects on micro-leakage. however, their interaction effect has not been reported yet. objectives: to evaluate the effect of contamination with a hemostatic agent on micro- leakage of total- and self-etching adhesive systems and the effect of chlorhexidine a...

Cl2, Br2, HBr, Br2/Cl2, and HBr/Cl2 feed gases diluted in Ar (50%–50% by volume) were used to study etching of p-type Si(100) in a rf inductively coupled, Faraday-shielded plasma, with a focus on the photo-assisted etching component. Etching rates were measured as a function of ion energy. Etching at ion energies below the threshold for ion-assisted etching was observed in all cases, with Br2/A...