Noncontact electrical metrology of Cu/low-k interconnect for semiconductor production wafers

We have demonstrated a technique capable of in-line measurement of dielectric constant of low-k interconnect films on patterned wafers utilizing a test key of ~50x50 \mu m in size. The test key consists of a low-k film backed by a Cu grid with >50% metal pattern density and <250 nm pitch, which is fully compatible with the existing dual-damascene interconnect manufacturing processes. The technique is based on a near-field scanned microwave probe and is noncontact, noninvasive, and requires no electrical contact to or grounding of the wafer under test. It yields <0.3% precision and 2% accuracy for the film dielectric constant

A near-field scanned microwave probe for spatially localized electrical metrology

We have developed a near-field scanned microwave probe with a sampling volume of approximately 10 micron in diameter, which is the smallest one achieved in near-field microwave microscopy. This volume is defined to confine close to 100 percent of the probe net sampling reactive energy, thus making the response virtually independent on the sample properties outside of this region. The probe is formed by a 4 GHz balanced stripline resonator with a few-micron tip size. It provides non-contact, non-invasive measurement and is uniquely suited for spatially localized electrical metrology applications, e.g. on semiconductor production wafers.Comment: 6 pages, 3 figures, submitted to Appl. Phys. Let

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Undiagnosed major risk factors in acute ischaemic stroke patients: frequency, profile, stroke mechanisms and outcome.

BACKGROUND AND PURPOSE: There is scarce clinical information about the clinical profile of patients with acute ischaemic stroke with previously undiagnosed major vascular risk factors (UMRFs). METHODS: This was a retrospective analysis of data from the Acute Stroke Registry and Analysis of Lausanne registry between 2003 and 2018 with univariate and multivariate logistic regression analyses comparing clinical profiles of patients with UMRFs to patients with at least one previously diagnosed MRF (DMRF). RESULTS: In all, 4354 patients (median age 70 years [interquartile range 15.2], 44.7% female) were included after excluding 763 (14.9%) for lack of consent and three for missing information. Amongst 1125 (25.8%) UMRF patients, 69.7% (n = 784) had at least one newly diagnosed MRF and the others none. The newly detected MRFs were dyslipidaemia (61.4%), hypertension (23.7%), atrial fibrillation (10.2%), diabetes mellitus (5.2%), ejection fraction <35% (2.0%) and coronary disease (1.0%). Comparing UMRF patients to DMRF patients, multivariate analysis showed a positive association with lower age, non-Caucasian ethnicity, contraceptive use (<55 years old), smoking (≥55 years old) and patent-foramen-ovale-related stroke mechanism. A negative association was found with pre-stroke antiplatelet use and higher body mass index. Functional outcome did not differ. Cerebrovascular recurrences were similar between groups. CONCLUSIONS: In this large single-centre cohort, 69.7% of patients with acute ischaemic stroke and UMRF were newly diagnosed with at least one new MRF, the most common being dyslipidaemia, hypertension or atrial fibrillation. Patients of the UMRF group were younger, more often smokers and on contraceptives, and had more patent-foramen-ovale-related strokes

Megahertz-rate Ultrafast X-ray Scattering and Holographic Imaging at the European XFEL

13 pages, 5 figures. Supplementary Information as ancillary fileThe advent of X-ray free-electron lasers (XFELs) has revolutionized fundamental science, from atomic to condensed matter physics, from chemistry to biology, giving researchers access to X-rays with unprecedented brightness, coherence, and pulse duration. All XFEL facilities built until recently provided X-ray pulses at a relatively low repetition rate, with limited data statistics. Here, we present the results from the first megahertz repetition rate X-ray scattering experiments at the Spectroscopy and Coherent Scattering (SCS) instrument of the European XFEL. We illustrate the experimental capabilities that the SCS instrument offers, resulting from the operation at MHz repetition rates and the availability of the novel DSSC 2D imaging detector. Time-resolved magnetic X-ray scattering and holographic imaging experiments in solid state samples were chosen as representative, providing an ideal test-bed for operation at megahertz rates. Our results are relevant and applicable to any other non-destructive XFEL experiments in the soft X-ray range