We improve the method proposed by Yao et al (2003) to resolve the X-ray dust scattering halos of point sources. Using this method we re-analyze the Cygnus X-1 data observed with Chandra (ObsID 1511) and derive the halo radial profile in different energy bands and the fractional halo intensity (FHI) askeV . We also apply the method to the Cygnus X-3 data (Chandra ObsID 425) and derive the halo radial profile from the first order data with the Chandra ACIS+HETG. It is found that the halo radial profile could be fit by the halo model MRN (Mathis, Rumpl & Nordsieck, 1977) and WD01 (Weingartner & Draine, 2001); the dust clouds should be located at between 1/2 to 1 of the distance to Cygnus X-1 and between 1/6 to 3/4 (from MRN model) or 1/6 to 2/3 (from WD01 model) of the distance to Cygnus X-3, respectively.

Threshold voltage shift induced by negative stress voltage application in HfSiO x films was investigated. It was found that the threshold voltage shift is a summation of the voltage shifts due to interface state generation and the generation of traps. It was revealed that the contribution of trap generation, which rapidly increases with the injection of a small amount of holes, is the most influential component in a short term. In a long term, on the other hand, the trap generation, which proceeds linearly with the hole injection, becomes the predominant component, since it does not saturate for a long period.

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We have established the comprehensive understanging of PBTI and NBTI reliability of high-k/metal gate stacks. When discussing PBTI, it exhibits a universal relationship in terms of fast transient carrier traps and stress voltage due to the positive oxygen vacancies formation. Using metal gate for Tinv scaling is promising for those improving drain current without PBTI lifetime degradation. However, in the case of NBTI, interface state degradation becomes more serious with Tinv scaling. Thus, high quality interfacial layer, such as wet oxide interface, is promising for improvement of NBTI lifetime.

We have established a comprehensive understanding of the PBTI and NBTI reliability of high-k/metal gate stacks. PBTI is found to exhibit a universal relationship, in terms of fast transient carrier traps and stress voltage, due to the formation of positive oxygen vacancies near cathode. The use of metal gates for T inv scaling is promising for the improvement of drain current without PBTI lifetime degradation. However, in the case of NBTI, interface state degradation becomes more serious with T inv scaling. Thus, the use of a high quality interfacial layer, such as a wet oxide interface, is a promising solution for the improvement of NBTI lifetime.