The new approach in the determination of the dependency of sur-face charge density on semiconductor surface potential based voltage–capacity analysis of the depletion region of MIS-structures

摘要

The analysis algorithm of quasistatic C-V-characteristics of MIS-structures in the range of the depletion of the semi-conductor surface of main carriers of the charge are developed. This algorithm provides the quantitative determination of a concentration of doping impurity, the fflat bands voltage and efficient values of a capacity and a thickness of a gate insula-tor. On this data, obtained within the framework of the single experiment on the Al-SiO_2-(100) n-Si MOS-structure, dependencies of ψ_s(V_g),Q_s[ψ_s(V_g)] and V_i(V_g) (where ψ_s and Q_s — a surface potential and a density of the surface charge in n-Si, V_g —a gate potential, V_i— a voltage drop on an oxide) are reduced. These dependencies without any a priori information about the state of the electronic gas under the strong accumulation or deep inversion are found. Experimental curves of ψ_s(V_g) and Q_s[ψ_s(V_g)] are possible considered as the criterion of the correct of the theory of the semiconductor space charge region, take into account electron gas degeneration and quantum confinement effects, as observed maximum layered densities of electrons and holes exceed I0~(13)cm~(-2). The dependency of V_i(V_g) necessary to use under investigations of the conductivity through gate insulators, particularly, in cases their small and ultrasmall of the thickness, when the leakage current is defined basically by the tunnel effect.