Abstract

Dopant types and concentrations largely influence the electric properties of silicon (Si). Due to the existence of surface states and surface dipoles, the band bending occurs, which is essential to be evaluated[1]. In this work, we systematically study THz emission from the Si surface with different doping types and doping concentrations before and after treated by the buffered hydrogen fluoride (BHF). The results reveal that the THz emission has sensitive response to the surface potential in both amplitude and sign. It turns out that laser-induced terahertz emission spectroscopy (TES) provides a promising non-contact method to evaluate the local surface properties in a wafer scale.

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