In situ formation of nanometer-scale TiO_2/SiC functional compositional film on carbon fiber

In the toluene solution of the precursor Polycarbosilane (PCS) containing low- molecular-mass additive Ti(OC4H9)4, TiO2/SiC nanometer-scale functional compositional film with the surface TiO2 layer on CF was formed in situ by means of polymer-derived precursors. The effects of Ti (OC4H9)4 concentrations and the maturating time were studied on the densification and TiO2 particle size of surface layer. The compositions of film were TiO2 and SiC crystal by XRD. According to the results of ESCA analysis, Ti(OC4H9)4 compound oozed gradiently from the pre-ceramic PCS to the surface layer after maturating time of 100 h. In the conditions of 45wt% Ti (OC4H9)4 and 100 h maturation, the nanometer-scale TiO2 particles on continuous surface layer were formed by SEM photographs. The nanometer-scale TiO2/SiC functional compositional film can modify the resistance to oxidation of carbon fiber.

Impacts of test factors on heavy ion single event multiple-cell upsets in nanometer-scale SRAM

Single event multiple-cell upsets（MCU） increase sharply with the semiconductor devices scaling. The impacts of several test factors on heavy ion single event MCU in 65 nm SRAM are studied based on the buildup of MCU test data acquiring and processing technique, including the heavy ion LET, the tilt angle, the device orientation, the test pattern and the supply voltage; the MCU physical bitmaps are extracted correspondingly. The dependencies of parameters such as the MCU percentage, MCU mean and topological pattern on these factors are summarized and analyzed. This work is meaningful for developing a more reasonable single event test method and assessing the effectiveness of anti-MCU strategies on nanometer-scale devices.

Low-Dimensional Forest-Like and Desert-Like Fractal Patterns Formed in a DDAN Molecular System

Two kinds of forest-like and desert-like patterns are formed by thermal evaporation of 4-dicyanovinyl-N, Ndimethylamino-1-naphthalene （DDAN） onto SiO2 substrates. Based on thermal kinetics of the molecules on the substrate the transformation between the forest and desert patterns is due to two factors. The first one is the diffusion length, which is related to the deposition rate, the diffusion potential energy barrier and the substrate temperature. The second one is the strong interaction between the two polarity chemical groups of the molecules, which is beneficial to the formation of branches. Totally different patterns are also found on mica substrates, and are attributed to the anisotropic diffusion and the stronger interaction between DDAN molecules and the mica surface.

Measurement of the thermal transport properties of dielectric thin films using the micro-Raman method

The micro-Raman method is a non-contact and non-destructive method for thermal conductivity measurement.To reduce the measurement error induced by the poor fit of the basic equation of the original micro-Raman method,we developed a new basic equation for the heat source of a Gaussian laser beam.Based on the new basic equation,an analytical heat transfer model has been built to extend the original micro-Raman method to thin films with submicrometer-or nanometer-scale thickness.Ex-periments were performed to measure the thermal conductivity of dielectric thin films with submicrometer-or nanometer-scale thickness.The thermal resistance of the interface between dielectric thin films and their silicon substrate was also obtained.The obtained thermal conductivity of silicon dioxide film is 1.23W/(m.K),and the interface thermal resistance between silicon dioxide film and substrate is 2.35×10-8m2.K/W.The thermal conductivity and interface thermal resistance of silicon nitride film are 1.07W/(m.K)and 3.69×10-8m2.K/W,respectively.The experimental results are consistent with reported data.