Atomic scale fabrication of dangling bond structures on hydrogen passivated Si(0 0 1) wafers processed and nanopackaged in a clean room environment

Abstract

Specific surfaces allowing the ultra-high vacuum (UHV) creation of electronic interconnects and atomic nanostructures are required for the successful development of novel nanoscale electronic devices. Atomically flat and reconstructed Si(001):H surfaces are serious candidates for that role. In this work such Si:H surfaces were prepared in a cleanroom environment on 200mm silicon wafers with a hydrogen bake and were subsequently bonded together to ensure the surface protection, and allow their transportation and storage for several months in air. Given the nature of the bonding, which was hydrophobic with weak van der Waals forces, we were then able to de-bond them in UHV. We show that the quality of the de-bonded Si:H surface enables the “at will” construction of sophisticated and complex dangling bond (DB) nanostructures by atomically precise scanning tunneling microscope (STM) tip induced desorption of hydrogen atoms. The DB structures created on slightly doped Si:H samples were characterized by scanning tunneling microscopy and spectroscopy (STM/STS) performed at 4K. Our results demonstrate that DB nanostructures fabricated on UHV de-bonded Si(001):H wafers could be directly incorporated in future electronics as interconnects and parts of nanoscale logic circuits.