A quantitative model capturing pattern dependent effects and time evolution of the etch rate in Deep Reactive Ion Etching (DRIE) is presented. DRIE is a key process for pattern formation in semiconductor fabrication. Non-uniformities are caused due to microloading and aspect ratio dependencies. The etch rate varies over time and lateral etch consumes some of the etching species. This thesis con...

According to the manufacturer (Kodak pathe) of the LR-115 Type 2 films, which are widely used in environmental radioactivity studies, the exposed films should be etched in 10% solution of NaOH, while the temperature of the etching solution is to be kept at 60C. The optimum time of etching depends on different conditions; like geometry of the bath, temperature etc. To determine the optimal etchi...

The formation mechanism of SiGe nanorod (NR) arrays fabricated by combining nanosphere lithography and Au-assisted chemical etching has been investigated. By precisely controlling the etching rate and time, the lengths of SiGe NRs can be tuned from 300 nm to 1 μm. The morphologies of SiGe NRs were found to change dramatically by varying the etching temperatures. We propose a mechanism involvin...

This study assessed the effect of different etching time of hydrofluoric acid and ultrasonic cleaning of the etched ceramic surface on the resin microtensile bond strength stability to a feldspathic ceramic. The research hypotheses investigated were: (1) different etching time does not affect the adhesion resistance; (2) ultrasonic cleaning improves the adhesion resistance. Forty-eight (48) blo...

The in vitro dentin permeability of the constituents of two types of conventional phosphoric acid etching agents which had different viscosities, and their pH changes after being permeated dentin were investigated. It was recognized that, even though the etching was for a short time (one minute) followed by rinsing, the etching agents were still detected in the dentinal tubules which had permea...

This paper is a review of wet and dry etching of one of the most common types of glass: Pyrex. The paper analyzes the methods for increasing the glass etch rate in HF solutions, namely, annealing, concentration, ultrasonic agitation and temperature. The limitations of the wet etching of glass are also presented. Mashing layers commonly used for deep wet etching of glass are analyzed, in terms o...

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...

The process of etching is the most crucial part of the work of manufacturing printed circuit boards (PCB). In the etching process by nitric acid, a spent etching waste solution of composition 250 g/L HNO3, 30-40 g/L Cu, 30-40 g/L Sn, 30-40 g/L Pb and 20-25 g/L Fe is produced. High metal concentrations in the spent etching waste solution make it a viable candidate for the recovery of metals. Rec...

Some conventional machining methods have been developed to machine microelectrodes. However, these methods still require too much time and too many resources. This paper uses electrochemical etching as an alternative method for the simple and cheap fabrication of microelectrodes. Electrochemical etching is usually considered an appropriate method of producing sharp probes. However, it is possib...

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...