Realization of atomically controlled dopant devices in silicon

The characteristics of the scanning tunneling microscopy (STM) for both direct assembly of the atomically controlled dopant silicon devices and imaging of each step of the fabrication process with atomic resolution, are examined. Molecular beam epitaxy (MBE) and STM patterning was combined to obtain atomically controlled, planar semiconductor devices down to the ≈ 10 nm level by selectively doping silicon with phosphorus atoms, utilizing the self-terminating chemisorption of PH3 molecules on the exposed Si surface as the dopant source. The STM was also used to observe each stage of the process and monitor the integrity structure as it is being made. The evolution of a series of STM-defined, Si:P nanowires ranging from 6 to 80 nm in width were monitored at the identical point of the surface. It was observed that the STM-patterned devices retain their original shape and size during each stage of the UHV fabrication process.