Investigation of interface trap characteristics in 3D NAND flash memory with temperature dependency

Abstract In this paper, the characteristics of interface traps ( N it ) at poly-Si and bandgap-engineered tunneling oxide (BE-TOX) interface in 3D NAND flash memory were investigated at various temperatures. Program and erase (P/E) cycling tests were carried out up to 30 k with four different temperatures and a recovery test for 60 min was conducted. The interface traps were analyzed using both the subthreshold swing (SS) method and technology computer-aided design (TCAD) simulation. N it generation occurs due to cold hole (CH) tunneling and is explained by the reaction-diffusion (RD) model. The N it generation follows a power-law relation with respect to the cycle counts. Additionally, N it recovery behavior was well fitted to the stretched exponential function (SEF). The activation energy ( E a ) was extracted from the recovery behavior. Also, temperature-dependent hydrogen diffusion tendencies in the BE-TOX layer were observed through TCAD simulation.