Dresden 2006 – scientific programme

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HL: Halbleiterphysik

HL 50: Poster II

HL 50.107: Poster

Thursday, March 30, 2006, 16:30–19:00, P3

Calculation of the direct tunneling current in a Metal-Oxide-Semiconductor structure with one-side open boundary — •Ebrahim Nadimi — Technische Universität Chemnitz, Fakultät für Elektrotechnik und Informationstechnik, Reichenhainer Straße 70, D-09126 Chemnitz, Deutschland

The leakage current through the oxide of an n-channel Metal-Oxide-Semiconductor (MOS) structure with one-side-open boundary is numerically computed by applying an one-dimensional Schrödinger-Poisson self-consistent solver. By embedding the n-channel MOS in a well, which prevents the penetration of particles into the metallic gate, the potential profile, the bounded energy levels and spatial distributions of electrons in the quantized levels are calculated in the inversion regime. Penetration of electrons into the metallic gate with open boundary results in a broadening of the discrete bound states at the interface of the substrate with the oxide, transforming the bounded energy levels to the quasi- bound states. Starting from the continuity equation, a qualitative formula for the current in terms of the electrons* lifetime in the quasi-bound states is derived. Based on the determination of the energy level width by means of wave functions, we suggest a method to compute the lifetime, and subsequently, the tunnelling current across the potential barrier. The tunnelling current is computed for a MOS structure with Silicon oxide and Silicon nitride gate oxides. The computation results are compared against results obtained experimentally for similar structures, yielding an excellent agreement.