Electrical analysis and modeling of floating-gate fault

It is demonstrated that a floating gate transistor (FGT) is influenced by its topological environment. The equivalent gate-to-source voltage of the FGT depends on the initial charges trapped in the gate oxide, the surrounding potential of metal lines and the drain-to-source voltage of the FGT itself. An electrical study of the floating gate fault is presented. A theoretical model taking into account the influence of the transistor´s environment is proposed. Analytical expressions for the equivalent gate-to-source voltage are derived, and the FGTs electrical operation mode is analyzed. This model is validated by SPICE simulations and by actual device measurements. The problem of testing for FGTs is discussed