Schottky barrier field effect transistors based on individual catalytically-grown and undoped Si-nanowires (NW) have been fabricated and characterized with respect to their gate lengths. The gate length was shortened by the axial, self-aligned formation of nickel-silicide source and drain segments along the NW. The transistors with 10-30 nm NW diameters displayed p-type behaviour, sustained current densities of up to 0.5 MA/cm2, and exhibited on/off current ratios of up to 10(7). The on-currents were limited and kept constant by the Schottky contacts for gate lengths below 1 microm, and decreased exponentially for gate lengths exceeding 1 microm.

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Despite all prophecies of its end, silicon-based microelectronics still follows Moore's Law and continues to develop rapidly. However, the inherent physical limits will eventually be reached. Carbon nanotubes offer the potential for further miniaturization as long as it is possible to selectively deposit them with defined properties.

To study the impact of metal contamination on the quality of gate oxides, (100) silicon wafers were intentionally contaminated with copper from the backside. The in-diffusion of copper and/or oxidation were performed in a rapid thermal annealing system. Gate oxide areas with low breakdown fields of about 2-3 MV Icm were located in a pinhole detector and correlate very well with the contaminated areas revealed by Secco defect etching. Using various analytical tools the failure mechanism was found to be related to the formation of eu-rich precipitates at the Si0 2 /Si interface. Depending on the in-diffusion temperature (and hence on the supersaturation of Cu in Si), two different mechanisms were observed: At high supersaturation (1200 °C/30 s) Cu-rich silicide particles can bend, crack, and finally penetrate the oxide layer. At lower in-diffusion temperatures (900 °C/60 s) lens-shaped Cu silicides form at the Si0 2 /Si interface and reduce the oxide thickness,

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