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Etching Technique (etching + technique)
Selected AbstractsMicrohardness studies on as-grown (111) faces of some alkaline earth nitratesCRYSTAL RESEARCH AND TECHNOLOGY, Issue 6 2009P. V. Raja Shekar Abstract Single crystals of Sr(NO3)2, Ba(NO3)2 and Pb(NO3)2 are grown from their aqueous solutions at a constant temperature of 35 °C by slow evaporation technique. Crystals of size 8 to 10 mm along one edge are obtained in a period of 10 days. Chemical etching technique has been employed to study the dislocations in these crystals. The dislocations are randomly distributed and the dislocation density is about 104 to 105 /cm2. Microhardness studies are made on as,grown (111) faces of these crystals upto a load of 100 g. The hardness of the crystals increases with an increase in load and thereafter it becomes independent of the applied load. These results are discussed on the basis of reverse indentation size effect. Meyer index number n for these crystals is estimated at both low and high load regions. An analysis of hardness data of these crystals as well as some other cubic crystals like alums and alkali halates are discussed using Gilman,Chin parameter Hv/C44, where Hv is the microhardness and C44 is the shear constant. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Controlling and Testing the Fracture Strength of Silicon on the MesoscaleJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2000Kuo-Shen Chen Strength characterizations and supporting analysis of mesoscale biaxial flexure and radiused hub flexure single-crystal silicon specimens are presented. The Weibull reference strengths of planar biaxial flexure specimens were found to lie in the range 1.2 to 4.6 GPa. The local strength at stress concentrations was obtained by testing radiused hub flexure specimens. For the case of deep reactive ion-etched specimens the strength at fillet radii was found to be significantly lower than that measured on planar specimens. This result prompted the introduction of an additional isotropic etch after the deep reactive ion etch step to recover the strength in such regions. The mechanical test results reported herein have important implications for the development of highly stressed microfabricated structures. The sensitivity of the mechanical strength to etching technique must be accounted for in the structural design cycle, particularly with regard to the selection of fabrication processes. The scatter of data measured in the mechanical tests clearly illustrated the need to use a probabilistic design approach. Weibull statistics may be the appropriate means to describe the data, although a simple two-parameter Weibull model only provides a moderately good fit to the experimental data reported in this study. [source] An analysis of substrate effects on transmission-lines for millimeter-wave CMOS RFIC applicationsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2008Jin-Fa Chang Abstract A set of transmission lines (TLs) for millimeter-wave (MMW) CMOS RFIC applications was implemented in a standard 0.18 ,m CMOS technology and then postprocessed by CMOS-compatible inductively-coupled plasma (ICP) etching, which removed the silicon underneath the TLs completely. TL parameters such as characteristic impedance ZC, attenuation constant ,, phase constant ,, effective permittivity ,eff, minimum noise figure (NFmin), parallel capacitance/conductance C/G, and series inductance/resistance L/R, as a function of frequency were extracted. It was found that ,, ,eff, NFmin, C, and G were greatly improved after silicon removal. The state-of-the-art performances of the on-chip TLs-on-air suggest that they are very suitable for application to realize ultralow-noise MMW CMOS RFICs. Besides, the CMOS-compatible backside ICP etching technique is very promising for MMW system-on-a-chip applications. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 319,324, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23055 [source] Unintentionally doped InN grown onto an atomically flat AlN intermediate layer using plasma-assisted molecular beam epitaxyPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 7 2006K. R. Wang Abstract Unintentionally doped InN has been grown onto an atomically flat AlN intermediate layer on top of the Si(111) substrate using plasma-assisted molecular beam epitaxy (PA-MBE). Though there are lots of micrometer-size indium droplets randomly distributed on the top of the surface, the highest electron mobility of this InN thin film measured at room temperature by van der Pauw method is still higher than 1000 cm2/V s with a carrier concentration of 5,8.9 × 1018 cm,3. A symmetrical X-ray rocking curve is measured and the full-width-at-half-maximum (FWHM) of this sample is 1089 arcsec. In the meantime, the threading dislocation (TD) density of this material is estimated to around 9.8 × 108 cm,2 , 7.5 × 109 cm,2 depending on the probing regions that are studied by the etching technique and field-emission scanning electron microscopy (FE-SEM). (2 × 1) in situ reflection high-energy electron diffraction (RHEED) patterns show that this sample is grown under In-rich environment with possible In-terminated surface. From the FE-SEM pictures which were taken from the samples after 10 minutes etching in hydrochloride, the surface morphology shows In-polarity-like patterns that coincide with those procured in RHEED. To select and grow a high-quality laminated AlN as intermediate layer is believed to be the major step in obtaining this high electron mobility InN thin film on Si substrate. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] One-year clinical evaluation of a two-step self-etch adhesive with and without additional enamel etching technique in cervical lesionsAUSTRALIAN DENTAL JOURNAL, Issue 2 2010E Ozel Abstract Background:, The aim of this study was to determine the clinical performance of a two-step self-etch adhesive with and without additional enamel etching technique to advanced non-carious cervical sclerotic lesions. Methods:, Twenty-two patients (mean age = 51.5) having at least two pairs of non-carious cervical erosion/attrition/abfraction lesions with incisal or occlusal margins in enamel and gingival margins in dentine/cementum were included in the study. The two-step self-etch adhesive (AdheSE; Ivoclar-Vivadent) was either applied following the self-etch approach on both enamel and dentine (AdheSE non-etch), or a similar application including additional acid-etching of the enamel cavity margins with 37% phosphoric acid (AdheSE etch). Resin composite Point 4 was used for all 104 restorations. Restorations were evaluated at baseline and at one year according to the modified United States Public Health Service (USPHS) criteria. Data were analysed by using McNemar's test (p <0.05). Results:, There were no significant differences in the marginal adaptation both at the cervical and enamel margins between AdheSE non-etch and AdheSE etch groups (p >0.05). At one year, marginal discolouration was evident in the AdheSE non-etch group but it was not statistically significant from the AdheSE etch group (p = 0.12). Postoperative sensitivity was 5% at baseline and reduced to 2% at one year. Conclusions:, At one year, the two-step self-etch adhesive with and without additional enamel etching technique showed excellent clinical results to advanced non-carious cervical sclerotic lesions. [source] | ||||||||||