Impact of P/E Stress on Trap Profiles in Bandgap-Engineered Tunneling Oxide of 3D NAND Flash Memory

Abstract

The quantitative characteristics of traps created in the bandgap-engineered tunneling oxide (BE-TOX) layer and block layer after program/erase (P/E) stress-cycling in a 3D NAND flash memory were investigated. The trap spectroscopy by charge injection and sensing technique was used to obtain the distribution of traps in these layers. In the BE-TOX layer, significant traps were generated at 1.3 eV in the nitrogen-doped layer (N1) and increased by 48% in the fresh cell after P/E stress-cycling. The H bonds in the N1 are more likely to break during the stress-cycling and create neutral ≡ SiO • traps. In the block layer, however, trap generation was negligible after stress-cycling.INDEX TERMS 3D NAND flash memory, bandgap-engineered tunneling, program/erase cycling, trap profile, TSCIS

Investigation of endurance degradation for 3-D charge trap NAND flash memory with bandgap-engineered tunneling oxide

“…Interface traps (Nit) and bulk traps in the tunneling oxide (Not) are generated during P/E cycling stress [22,23,24,25,26], and the tunneling process is changed by the charges trapped in the bulk traps. The tunneling process for the degraded cell is shown in Fig.…”