Heterogeneous oxidation of Si(1 1 1) 7 × 7 monitored with Kelvin probe force microscopy

Laterally resolved topography and Contact Potential Difference (CPD) images, acquired during the exposure of clean Si(1 1 1) 7 × 7 to molecular oxygen at room temperature, show a heterogeneous oxidation process, without preference for step edges. The increase of and lateral changes in work function variations show that the CPD variations of the final oxide film are related to the silicon/oxide interface. The molecular Hِfer precursor has a pronounced influence on the development of the interface bonding.