Low-temperature electrical characterization of the Ti–Si(100) interface at the p-Si/SiGe/Si–Ti structure using Hall measurement analysis

Abstract

Electrical characterization of a Ti–Si Schottky contact has been investigated using low-temperature Hall experiment analysis in the p-Si/SiGe/Si–Ti structure. In this approach, the density of a two-dimensional hole gas (2DHG) formed in the SiGe quantum well was a measure of charged metal-induced gap states. The Schottky barrier height (SBH) and the density of interface charges nint were evaluated via simulation of 2DHG density nh versus bias voltage applied to a Schottky gate. It was found that the density of interface charges depends on the position of the SiGe quantum well with respect to the Si–Ti interface irrespective of the bias voltage. Finally, the density of interface states was assessed via cap layer dependence of SBH and nint according to the mid-gap pinning model.