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Full-Text Articles in Physics
Characterization Of Ultrathin Gate Dielectrics And Multilayer Charge Injection Barriers, Edwin M. Dons
Characterization Of Ultrathin Gate Dielectrics And Multilayer Charge Injection Barriers, Edwin M. Dons
Dissertations
Since the invention of the first integrated circuit, the semiconductor industry has distinguished itself by a phenomenally rapid pace of improvements in device performance. This trend of ever smaller and faster devices is a result of the ability to exponentially reduce feature sizes of integrated circuits, a trend commonly known as "scaling". A reduction of overall feature sizes requires a simultaneous reduction in the thickness of the gate dielectric, SiO2, of a MOSFET. Gate oxides in the ultrathin regime (<35 A) feature a large direct tunneling leakage current. The presence of this leakage current requires a reevaluation of standard characterization techniques as well as a reevaluation of the continued usefulness of SiO2 as the gate dielectric of choice for future applications. On the other hand, a thorough understanding of …
Understanding The Origin Of The Recovery Of Superconductivity In Halogenated Ybco Single Crystal : Atomic Structure Study, Lamine Mohamed Kollakoye Dieng
Understanding The Origin Of The Recovery Of Superconductivity In Halogenated Ybco Single Crystal : Atomic Structure Study, Lamine Mohamed Kollakoye Dieng
Dissertations
The recovery of superconductivity in underdoped YBa2Cu3O6+y (YBCO) by exposure to bromine, iodine, chlorine and fluorine is a long-standing problem which has not been clearly resolved. The key question concerns the role of these halogens in the lattice. In order to shed light to this problem, we have performed multiple-edge x-ray absorption fine structure (XAFS) measurements about the Y K, Ba L3, I L3, Cu K and Br K-edges at room temperature on brominated (non-brominated) and iodinated (non-iodinated) YBCO single crystals. Our XAFS results at the Br K (brominated) and I …
Statistical Study Of Solar Radio Bursts, Gelu-Marius Nita
Statistical Study Of Solar Radio Bursts, Gelu-Marius Nita
Dissertations
The peak flux distribution of 40 years of solar radio burst data recorded by NOAA, as a function of frequency and time over a wide range of frequencies, was investigated to quantify the potential impact of radio bursts on wireless systems. Tables of fit parameters, which can be used to find burst occurrence rates in a number of frequency ranges, are presented. The typical power-law index of number density distribution, -1.8, is similar to that found in many hard X-ray studies. Significant changes were found in power-law index with frequency. The results may be useful for designers of current and …
High Resolution Solar Observations In The Context Of Space Weather Prediction, Guo Yang
High Resolution Solar Observations In The Context Of Space Weather Prediction, Guo Yang
Dissertations
Space weather has a great impact on the Earth and human life. It is important to study and monitor active regions on the solar surface and ultimately to predict space weather based on the Sun's activity. In this study, a system that uses the full power of speckle masking imaging by parallel processing to obtain high-spatial resolution images of the solar surface in near real-time has been developed and built. The application of this system greatly improves the ability to monitor the evolution of solar active regions and to predict the adverse effects of space weather. The data obtained by …