Uniform Tendency of Surface Dipoles Across Silicon Doping Levels and Types of H-Terminated Surfaces

Abstract

The termination of surface-dangling bonds on silicon through hydrogen atoms, also known as Si–H, can achieve chemical passivation and reduce surface states in the electronic bandgap, thus altering electronic properties. Through a comprehensive study of doping levels (10¹⁴–10²⁰ cm⁻³) and types (n and p), a consistent surface dipole trend induced by Si–H termination is discovered. It is achieved by redistributing surface charges and establishing thermal equilibrium with the chemical bond. To resolve this, the surface work function, surface electron affinity, and the energy difference between the valence band and the Fermi level are measured by employing the Kelvin probe, X-ray photoelectron spectroscopy, and photoelectron yield spectroscopy methods. These findings are further validated through ab initio simulations. This finding has immense implications not only for eliminating electronic defects at semiconductor interfaces, which is crucial in microelectronics but also for developing and engineering hybrid interfaces and heterojunctions with controlled electronic properties.