Comparison of carrier profiles from spreading resistance analysis and from model calculations for abrupt doping structures

Abstract

Very abrupt doping structures grown by Si molecular beam epitaxy are investigated by spreading resistance (SR) analysis. The corresponding SR profiles reveal strong carrier spilling effects. To calculate the ‘‘on bevel’’ carrier concentrations of these structures, a formalism is developed which is based on the Poisson–Boltzmann equation. Qualitative agreement between the model calculation and the SR data is established.