Study of the Gate-Sensing and Channel-Sensing Transient Analysis Method for Monitoring the Charge Vertical Location of SONOS-Type Devices

The gate-sensing and channel-sensing transient analysis method is studied in detail. This method introduces an additional gate-sensing capacitor to be compared with the conventional channel-sensing one. Sensing in both modes provides two equations that are suitable to solve for two variables—the charge density ( $Q$) and the average charge vertical location ( $x$). In this paper, the principle of this method is discussed in detail. Several factors that affect the measurement accuracy are also analyzed. The power of this method is demonstrated by program/erase cycling and data retention tests. This method is indeed a powerful tool for detailed understanding of trapping dynamics.