James Brennan

On the Capacitance Coupling Ratios of a Source-Side Injection Flash Memory Cell

A new method for measuring the capacitance coupling ratios of non-volatile memory cells is reported. This method is applied to the source-side-injection (SSI) Flash cell. Conventional extraction methods are complicated by the presence of the select transistor. In this work the coupling ratios of a source-side injection Flash memory cell are extracted from source-follower voltage (Vsf) measurements of the Flash cell and a reference cell, in the read mode. Validity of these coupling ratios and a two-transistor memory cell representation under programming condition are confirmed via two-dimensional device simulations. These coupling ratios provide a solid base for a multilevel Flash cell circuit model.

The reliability of multilevel analog memory in a voice storage and playback system using source-side injection flash

The reliability of a multilevel analog memory is mainly determined by data retention, cycling endurance, and read and write disturb. This storage system retains a voice message for 10 years and can record continuously for 50 K cycles. It can tolerate up to 300 single cell retention shifts >50 mV and still meet THD<0.5% and SINAD>32 dB.