In this letter, the uniform 4H silicon carbide (SiC) mesopores was fabricated by pulsed electrochemical etching method. The length of the mesopores is about 19 μm with a diameter of about 19 nm. The introduction of pause time (T off) is crucial to form the uniform 4H-SiC mesopores. The pore diameter will not change if etching goes with T off. The hole concentration decreasing at the pore tips d...

Isotropic etching of silicon in HF-based solutions is expected to be controlled by the diffusion of fluoride to the silicon surface. In order to gain quantitative understanding of the process, we studied etching of silicon in HF/HNO3/H2O via circular mask openings and compared the results with the theoretical expectations. The cavity edges due to etching under the mask were analyzed with a high...

Background and Aim: Recurrent caries and low bond strength are the main causes of composite restorations failure. This study sought to assess the effect of chlorhexidine (CHX) on micro-shear bond strength (MSBS) to dentin of a fourth generation adhesive system and a universal bonding agent after aging. Materials and Methods: This in vitro study used 32 extracted third molars and 3-5mm thick de...

Introduction: Adhesive dentistry faces complex clinical situations, which require the dentist to be able choose best adhesive protocol offered by universal adhesives. Objective: To present current information about performance in bond strength according etching technique used adhesives, evaluating total technique, selective enamel etching, self-etch and bonding special situations. Methodology: ...

The aim of this study is to investigate the influence of different etching times on demineralized dentin surface morphology using scanning electron microscopy and qualitative line microanalysis of chemical structure. Two sample groups, consisting of 30 first premolar teeth in each group, were established. Teeth were cut at the half-distance between the enamel-dentin junction and the pulp. The f...

This paper shows that the reflectance in silicon nanowires (SiNWs) can be optimized as a function of the area of silicon substrate where the nanostructure growth. SiNWs were fabricated over four different areas of silicon substrates to study the size effects using electroless etching technique. Three different etching solution concentrations of silver nitrate (AgNO3) and hydroflu...

Silicon nanostructure surface fabricated from metal-assisted etching have been demonstrated as high sensitivity matrix-free laser desorption/ionization mass spectrometry chip. The silicon nanostructure morphology was found to have direct effect to the mass spectrometry ionization efficiency. Creation of different silicon nanostructure morphologies by changing the metal thickness, etching time a...

Deep-etch-defined GaAs/Al0.3Ga0.7As square features of multiquantum well material, with dimensions as small as 160 nm, have been fabricated using magnetron reactive ion etching ~MIE!. Luminescence spectroscopy shows confinement of charge carriers to the features’ center. The effects of rf power and etching time on the luminescence efficiency of these features and its concomitant etch-induced da...

The authors report a new, important phenomenon: photo-assisted etching of p-type Si in chlorinecontaining plasmas. This mechanism was discovered in mostly Ar plasmas with a few percent added Cl2, but was found to be even more important in pure Cl2 plasmas. Nearly monoenergetic ion energy distributions (IEDs) were obtained by applying a synchronous dc bias on a “boundary electrode” during the af...