The dc current gain dependence of InGaP/GaAs heterojunction bipolar transistors (HBTs) on subcollector and etch-stop doping is examined. Samples of InGaP/GaAs HBTs having various combinations of subcollector doping and etch-stop doping are grown, and large area (60 m 60 ( ) HBTs are then fabricated for dc characterization. It is found that the dc current gain has a strong dependence on the dopi...

introduction: retention of fiber reinforced composite posts depends on the bond strength between post and cement, and cement and root dentin. the aim of this study is to evaluate the bond strength of one type of fiber post to radicular dentin with different adhesive cements. materials and methods: crowns of 44 caries-free, human premolar were removed 2 mm below the cej and the roots were endodo...

The magnetic tunnel junction (MTJ)-related materials such as CoFeB, CoPt, MgO, and Ru, and W were etched using CH3OH in a pulse-biased inductively coupled plasma system and the effect of bias pulsing (100% 30% duty percentage) on the etch characteristics of the MTJ-related materials was investigated at the substrate temperature of 200 degrees C. The etch selectivity of MTJ-related materials ove...

Electrical through-wafer interconnects (ETWI) are often integrated with inertial sensors for harsh liquid environment applications. Devices with metal interconnects are very susceptible to corrosion in aquatic environments. An alternative approach is to form highly doped, conductive polysilicon through the wafer from the back side (unexposed to harsh environments) to the front side of the devic...

Abstract: In this paper, a DRIE process for fabricating MEMS silicon trenches with a depth of more than 250 m is described. The DRIE was produced in oxygen-added sulfur hexafluoride (SF6) plasma, with sample cooling to cryogenic temperature using a Plasmalab System 100 ICP 180 at different RF powers. A series of experiments were performed to determine the etch rate and selectivity of the some m...

microleakage can be responsible for tooth hypersensitivity, secondary caries, and the possibility of pathological pulp alterations in restored teeth. recently, alternative methods for tooth preparation such as laser irradiation have been studied; but there are limited studies on primary teeth. the aim of this in vitro study was to compare the degree of microleakage of composite restorations pre...

AIM The aim of this study was to assess the influence of surface texture and etching technique on surface roughness (Ra) and bond strength (BS) to enamel and to determine if a correlation exists between them. METHODS AND MATERIALS Fifty enamel blocks were either roughened with 600-grit SiC paper or polished with diamond pastes. After establishing ten test groups (n=5), the initial Ra measurem...

background and aims. effect of surface treatments on repair bond strength of aged composite resins might be different due to their dissimilar fillers. the aim was to evaluate the effect of different surface treatments on repair micro-shear bond strength (µsbs) of silica- (spectrum tph) and zirconia-filled (filtek z250) composite resins. materials and methods. twenty-seven composite resin blocks...