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Correlated evolution of barrier capacitance charging, generation, and drift currents and of carrier lifetime in Si structures during 25 MeV neutrons irradiation Appl. The relaxation behaviour of supersaturated iron in single-crystal silicon at 500 to 750°C Comment on " Lifetime recovery in ultra-highly titanium-doped silicon for the implementation of an(More)
John H. Martin, who discovered widespread iron limitation of ocean productivity, proposed that dust-borne iron fertilization of Southern Ocean phytoplankton caused the ice age reduction in atmospheric carbon dioxide (CO2). In a sediment core from the Subantarctic Atlantic, we measured foraminifera-bound nitrogen isotopes to reconstruct ice age nitrate(More)
Fixed nitrogen (N) is a limiting nutrient for algae in the low-latitude ocean, and its oceanic inventory may have been higher during ice ages, thus helping to lower atmospheric CO2 during those intervals. In organic matter within planktonic foraminifera shells in Caribbean Sea sediments, we found that the 15N/14N ratio from the last ice age is higher than(More)
In the ocean, the chemical forms of nitrogen that are readily available for biological use (known collectively as 'fixed' nitrogen) fuel the global phytoplankton productivity that exports carbon to the deep ocean. Accordingly, variation in the oceanic fixed nitrogen reservoir has been proposed as a cause of glacial-interglacial changes in atmospheric carbon(More)
Defect concentrations in low-k organosilicate glass films deposited on high-resistivity silicon were measured with electron-spin resonance. Bulk dangling bonds were detected. Both plasma exposure and ultraviolet exposure were used. During argon electron cyclotron resonance plasma exposure, ion and photon bombardment increased the measured defect(More)
Vacuum-ultraviolet irradiation produces trapped charges in dielectrics. The trapped charges often generate self-consistent electric fields. A Monte Carlo simulation coupled with a Poisson equation solver is used to model the relationship between the irradiation photon flux and electrostatic potential. The simulation includes photoconduction, photoemission,(More)
Defects in low-k organosilicate glass produced during air and nitrogen plasma exposure were investigated. The defects, through the measurements of electron-spin resonance and Fourier-transform infrared spectroscopy, were found to be silicon-dangling bonds. Air-plasma exposure increases the defect concentrations by breaking silicon–hydrogen bonds.(More)
The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron. Greater atmospheric dust deposition could have fertilized the(More)
More and more high-and low-k dielectrics are used in microfabrication today. However, as is well known, these materials are easily damaged during processing or during operation in a device. Sources of damage include plasma and/or VUV exposure, water uptake, free radicals as well as cosmic rays. A description of the damage effects on dielectrics from water(More)
The effects of vacuum ultraviolet ͑VUV͒ ͑7.2 eV͒ and UV ͑4.9 eV͒ irradiation on hafnium-oxide dielectric layers were studied with electron-spin resonance to detect defect states. Silicon dangling-bond defects ͑P b centers͒ and positively charged oxygen vacancies ͑EЈ centers͒ were detected with g-factor fitting. VUV irradiation increases the level of P b(More)