Electron filling in phosphorus donors embedded in silicon nanostructures observed by KFM technique

Abstract

Low Temperature Kelvin Probe Force Microscope (LT-KFM) is used to investigate the surface potential of phosphorus-doped thin silicon-on-insulator field effect transistor. Ionized phosphorus donors induce local potential modulations due to their Coulomb potential. Here, we show results of electron injection into neighboring donors by gradually increasing the backgate voltage. Such single donor neutralization can be observed if neighboring donors are isolated from each other by a potential barrier. The potential barrier can be directly related to the inter-donor distance, as shown by a statistical analysis of donor pairs.