A quasi-hydrodynamic simulation of electrical conductivity in selectively doped submicrometer-sized layered structures and island films in high electric fields

Abstract

Mathematical simulation is used to study special features of the high-field drift of electrons that occurs in submicrometer-sized n ⁺-n-n ⁺ structures with an appreciable impurity-concentration profile in the their high-resistivity region. A quasi-hydrodynamic description of the electron drift is used. In this description, the dependences of the charge-carrier mobility and energy-relaxation time on the electron temperature, the thermodiffusion component of the electron flow, and the divergence of the electron-temperature flux are taken into account. It is shown that sectioning of the high-resistivity carrier-flight n-type region by additional low-resistivity n ⁺-type inclusions with submicrometer thickness appreciably reduces the electron-gas temperature and increases the effective mobility of the charge carriers and, consequently, the high-field electrical conductance of the structure owing to a corresponding increase in the drift velocity.