In this study we have investigated the effect of starting GaAs semi-insulating substrate surface (polished / unpolished), type of mask used (photoresist / Nickel) and RIE parameters (pressure and power) on the surface smoothness/morphology of the etched via-walls and resultant etch profiles with CCl2F2 / CCl4 gas chemistry. The ultimate aim of the study has been to develop a reliable via-hole g...

Background and aims. Er:YAG laser irradiation has been claimed to improve the adhesive properties of dentin; therefore, it has been proposed as an alternative to acid etching. The aim of this in vitro study was to investigate the shear bond strength of an etch-and-rinse adhesive system to dentin surfaces following Er:YAG laser and/or phosphoric acid etching. Materials and methods. The roots of ...

Wafer and die level uniformity effects in Deep Reactive Ion Etching (DRIE) are quantitatively modeled and characterized. A two-level etching model has been developed to predict non-uniformities in high-speed rotating microstructures. The separation of wafer level and die level effects is achieved by sequentially etching wafers with uniformly distributed holes. The wafer level loadings range fro...

This paper proposes a new technique to engineer the Fin channel in vertical GaN FinFET toward straight and smooth sidewall. Consequently, wet etching TMAH solution is detailed; we found that m-GaN plane has lower surface roughness than crystallographic planes with other orientations, including a-GaN plane. The grooves slope (Cuboids) at base are also investigated. agitation does not assist Cubo...

Surface morphology evolution mechanisms of InGaN/GaN multiple quantum wells (MQWs) during GaN barrier growth with different hydrogen (H2) percentages have been systematically studied. Ga surface-diffusion rate, stress relaxation, and H2 etching effect are found to be the main affecting factors of the surface evolution. As the percentage of H2 increases from 0 to 6.25%, Ga surface-diffusion rate...

We investigated fs-laser structuring of YAG crystals at high writing velocities up to 100 mm/s using a commercial 10 MHz system supplied by Coherent Inc. and selective etching these structures for fabrication ultrahigh aspect ratio microchannels. Usage diluted acid mixture 22% H 3 PO 4 24% 2 SO accelerated the process significantly an parameter D 11.2 μm /s, which is three times higher than pre...