Formation and Thermal Stability of sub-10 nm Carbon Templates on Si(100)

We report a lithographic process for creating high-resolution (<10 nm) carbon templates on Si(100). A scanning electron microscope, operating under low vacuum (10E-6 mbar), produces a carbon-containing deposit ("contamination resist") on the silicon surface via electron-stimulated dissociation of ambient hydrocarbons, water and other adsorbed molecules. Subsequent annealing at temperatures up to 1320 K in ultra-high vacuum removes SiO2 and other contaminants, with no observable change in dot shape. The annealed structures are compatible with subsequent growth of semiconductors and complex oxides. Carbon dots with diameter as low as 3.5 nm are obtained with a 200 us electron-beam exposure time.Comment: 13 pages, 4 figure

Development and Performance of the Nanoworkbench: A Four Tip STM for Electrical Conductivity Measurements Down to Sub-micrometer Scales

A multiple-tip ultra-high vacuum (UHV) scanning tunneling microscope (MT-STM) with a scanning electron microscope (SEM) for imaging and molecular-beam epitaxy growth capabilities has been developed. This instrument (nanoworkbench) is used to perform four-point probe conductivity measurements at micrometer spatial dimension. The system is composed of four chambers, the multiple-tip STM/SEM chamber, a surface analysis and preparation chamber, a molecular-beam epitaxy chamber and a load-lock chamber for fast transfer of samples and probes. The four chambers are interconnected by a unique transfer system based on a sample box with integrated heating and temperature-measuring capabilities. We demonstrate the operation and the performance of the nanoworkbench with STM imaging on graphite and with four-point-probe conductivity measurements on a silicon-on-insulator (SOI) crystal. The creation of a local FET, whose dimension and localization are respectively determined by the spacing between the probes and their position on the SOI surface, is demonstrated.Comment: 39 pages, 15 figure