Fast and precise subthreshold slope method for extracting gate capacitive coupling coefficient in flash memory cells

A fast and precise subthreshold slope method for extraction of gate capacitive coupling coefficient is substantially confirmed by experimental data from three types of flash memory cells: stacked gate, sidewall source-side injection (SSI), and split-gate cells. This new method furnishes promising potentials: (i) it can eliminate the effect of process variations; (ii) the traditional source or drain capacitive coupling measurement becomes unnecessary; (iii) only a few DC measurements are needed; and (iv) even dummy transistors can be removed. Therefore, the method is highly suitable as an in-line process monitor.