A new technique for measuring coupling coefficients and 3-D capacitance characterization of floating-gate devices

The characteristics of the capacitance in floating-gate devices are comprehensively investigated. The capacitive coupling coefficient (α_c) between the control and floating gates is measured simultaneously, by a new technique, with the shift in threshold voltage during the programming. The present results are compared with those found from other methods and the dependence of α_c on applied voltages is examined. It is also shown that the α_c -data from a set of test patterns with varying floating-gate widths leads to the 3-D characterization of small geometry floating gate devices down to subfemto Farads. These measured characteristics are discussed in correlation with the effects of both the short channel length and of the narrow gate width