Extraction of Interface Trap Density in the Region Between Adjacent Wordlines in NAND Flash Memory Strings

摘要

A new method to extract the interface trap density () on the surface of the Si region between adjacent wordlines (WLs—called space region) in flash devices is presented in this letter. The is successfully extracted by applying charge pumping (CP) method, TCAD simulation, and modified equations. The CP current of single WL and electrically tied two WLs are measured using fixed-base CP measurement as a function of pass bias. In addition, an effective space area for CP is extracted by TCAD simulation, and the equation, which is used to extract , is modified to extract separated s in the channel and the space regions. We confirm that our method is accurate by comparing the measured with the calculated one.