Investigation and Compact Modeling of the Time Dynamics of the GIDL-Assisted Increase of the String Potential in 3-D NAND Flash Arrays

This paper presents a detailed analysis of the time dynamics of the gate-induced drain leakage (GIDL)-assisted increase of the string potential in vertical-channel 3-D NAND Flash arrays. The string potential and the GIDL current waveforms are first studied with close attention by means of technology computer-aided design simulations, highlighting the major phases of their time evolution. A compact model able to reproduce the string behavior is then presented and successfully tested for a variety of electrical waveforms applied to the string contacts, for increasing number of cells in the string and for different string geometrical parameters. The compact model represents a valuable tool to design and optimize the GIDL conditions for the best erase performance.