Characterization of moving bits (MBs) and QBD in wet/dry tunnel oxides for floating gate type nonvolatile memory (FG-NVM) applications

A critical problem of floating gate type nonvolatile memories (FG-NVMs) used in flash memories or EEPROMs is anomalous charge loss which leads to threshold voltage (Vt) shifts on a time scale of months or years at room temperature. The number of these moving bits (MB's) is greatly affected by the nature and properties of the tunnel oxide that is used in the NVM technology. In this paper we compare different types of tunnel oxides and determine the impact on the MB issue with different measurement techniques.